"No chance of following him," Joe muttered. "He might have led us to the gang's hideout, too."
Just then the other man trudged by. The boys waited tensely until the bulky figure reached the gate.
"Joe," whispered Frank, "we can still find out who Big Al's spy in town is."
Cautiously the boys started toward the cemetery gate. They could hear the big man ahead, slipping and slithering along over the stony, snow-covered hill. The Hardys followed him as closely as they dared, moving furtively from one patch of scrub brush to another.
Suddenly Frank stopped short to listen. He thought he had heard a noise behind them and seized his brother's arm to alert him. Startled, Joe slipped and nearly fell. A shower of stones cascaded down the hill!
There was silence on the dark slope. Frank and Joe stood motionless, listening intently. They could imagine the burly figure ahead listening as well. Then, from behind them, another rock came tumbling down.
Joe nudged Frank. "We didn't cause that! Someone's following us!"
Had the thin man spotted them, the Hardys wondered, and doubled back to stalk them? Or had a third person been in the cemetery, as they suspected?
The brothers scanned the hill above, but could see no one. "He's probably hiding behind boulders or scrub," Frank whispered.
After a while the Hardys thought they detected sounds of movement below them. Warily they descended, alert for any possible attack from the rear.
By the time they reached the foot of the hill, Frank and Joe had drawn close enough to their quarry to spot his shadowy figure disappearing into the ghost town. The boys trod stealthily on the snow-crusted wooden sidewalk, hugging the buildings. Ahead they could hear the man's footsteps and see his bulky, muffled shape. Suddenly he vanished into the sagging shell of a deserted building.
The Hardys quickened their pace and peered around the corner of the building. They were just in time to see the man emerge from the rear. He whirled about and ran to the far side of the adjoining building.
Frank darted in pursuit and saw the man return to the street. When Frank reached the sidewalk again, Joe was at his elbow, silent as a shadow. Ahead, the man was hurrying down the street toward the other end of town.
"He knows he's being followed," Joe whispered, "and is trying to shake us."
"Come on, or we'll lose him!" Frank urged.
Flinging caution aside, the boys broke into a run, their steps pounding on the plank walk. Apparently their quarry heard them and immediately stepped up his own pace. A moment later the dim figure melted into the darkness between two old buildings. Frank and Joe reached the spot in a few seconds.
"This way!" Frank urged in a low voice, and the Hardys plunged into the shadowy gloom of the narrow passageway.
Behind the two structures, the brothers found themselves in an area overgrown with weeds and brush which merged into the trees on the hillside. Frank and Joe halted, straining their eyes in the darkness and listening intently. Nothing could be heard but the wind-then the howl of a wolf somewhere beyond the ridge.
"Looks as if he's given us the slip," Joe muttered.
The boys flicked on their flashlights and searched about. They finally picked out the fugitive's prints, but his tracks led to the hard-trampled roadway and became indistinguishable. Baffled, the Hardys started back through the ghost town on their way to Hank's cabin.
"Of all the luck!" Joe grumbled. "We almost had our hands on that spy!"
"At least we've learned one thing about him," Frank said thoughtfully.
"What's that?"
"His nickname. The man he met in the cemetery called him 'Slip Gun.' "
"You're right! I almost forgot," Joe said. "Maybe it'll help us trace him, if we can find out what it means.
Any idea?"
Frank shook his head. "Not a glimmer, except that it sounds like a cowboy expression. Maybe Hank can tell us."
As they approached Ben Tinker's place, the brothers noticed that the windows were dark. Frank and Joe paused at the shack to listen, and heard a steady wheezing snore coming from inside.
"Good thing the old man's asleep"-Frank chuckled-"or he might have started shooting at us!"
The Hardys resumed their pace. They were about to go past the deserted dance hall next door, when suddenly they froze in their tracks. Both Frank and Joe felt the hair on their necks rise and cold chills sweep up and down their spines.
From the abandoned hall, through the moan of the wind, came the sound of piano playing.
Tinker's ghost music!
CHAPTER VII.
A Rooftop Struggle THE wind suddenly died down and in the eerie silence Frank and Joe again heard the tinkle of the piano keys coming from the deserted dance hall.
Joe murmured, "Here's one mystery we can solve tonight! Let's find out what goes on in here!"
"Right."
Moving lightly over the wooden sidewalk, the boys approached the dance-hall entrance. The weird, tuneless music stopped.
Frank and Joe looked at each other. "Maybe we've scared the spook away," Frank whispered half jokingly.
As if in answer, the music started once more. This time both the treble and bass keys of the piano sounded.
Quickly the Hardys drew flashlights from their jacket pockets and stepped inside. The searchers snapped on their flashlights and played the beams about the interior.
The music stopped again.
The room was sparsely furnished with a few rickety tables and chairs, heavily coated with dust. Ancient oil-lamp chandeliers, festooned with cobwebs, dangled from the ceiling.
At that moment the piano resumed its tinkling. Outside, the wind howled and shutters banged.
"Boy! This place is really creepy!" said Joe with a shudder.
Frank gripped his brother's arm. "Look there!"
The boys' lights now fell on a raised dais at one end of the room. On it stood a battered upright piano.
The Hardys stared in astonishment as the music continued. "The piano's playing by itself!" Joe exclaimed.
Quickly the brothers crossed the room and Frank lifted the top of the old piano. He shone his flashlight inside. There was a sudden squeaking and twanging of wires.
"For Pete's sake!" he burst out, as several rats scampered out of the piano, jumped down to the floor, and scurried away.
The boys laughed heartily. "There goes Tinker's ghost music," Frank said.
"Talented rats." Joe grinned.
Suddenly, from the direction of the doorway, they heard the sidewalk creak. The boys whirled as a low, flat voice snarled, "You kids have been askin' for it!"
Frank and Joe barely had time to glimpse a head-masked by a ghostlike hood with eyeholes -above the swinging doors. Then a gloved hand jerked into view, clutching a short-barreled revolver, the thumb cocking back the hammer. There was a spurt of flame.
Bang! A bullet whistled across the room and thudded into the piano. The Hardys dived from the dais, snapping off their flashlights and crashing into the tables and chairs below.
As the echoes of the shot died away, Frank picked up a broken chair and hurled it in the general direction of the gun flash.
There was a grunt as the chair connected, then the Hardys could hear the gunman's feet scraping across the floor. He was stalking them in the darkness!
The boys separated instinctively to divide his attention. Frank crept off to the right and Joe to the left.
Suddenly Frank sprang to his feet. In two long strides he reached the window and leaped through it into the darkness outside.
Crash! Bang! There was no glass in the window, but Frank's weight had carried away the cross-pieces of the frame. He landed feet first. A moment later he saw a figure struggling through the window, grunting with the effort. The masked man!
Frank dashed around the corner of the dance hall. When he reached the back, he skidded to a halt at a high fence that was blocking his way. Hearing the gunman's steps behind him, Frank vaulted the fence and fell in a heap on the other side.
The gunman leaped a moment later. Frank held his breath. He could see the man silhouetted against the dim light of the sky-then darting off into the darkness.
Frank jumped up and dashed into a ramshackle building that stood next to the dance hall. But the hooded man evidently had spotted the boy's move, for Frank heard steps pounding in pursuit.
Without hesitation he raced through the front door and out onto the slippery, snowy sidewalk.
There was no time to find cover. The gunman was hot on his heels. In desperation, Frank ran straight down the open street. As he sped along, he wondered what had happened to Joe.
Flinging a glance over his shoulder, Frank saw the hooded gunman raise his arm to fire. Zing! The bullet whistled past Frank's head and ricocheted off a metal store sign.
Just ahead, to the left, was an old hitching rail. Frank recalled that it stood in front of the ghost town's abandoned hotel. He cut across the street and dashed into the narrow side yard of the hotel.
A flight of outside stairs slanted up the wall of the building. Frank mounted the steps two at a time. At the top was a rickety wooden balcony, which sagged under Frank's weight as he stepped onto it.
"Now what?" the young detective wondered. Had he worked himself into a corner? Frank's heart thudded as he heard the gunman's footsteps on the wooden walk below.
Just out of reach, the overhanging roof of the hotel loomed in the blackness. There was no place else to go, so Frank leaped up for the edge.
His fingers dug into the broken shingles and he swung himself onto the rear slope of the snow-covered roof. Meanwhile, the hooded gunman had already started up the stairs. Frank heard his clattering footsteps as he reached the balcony platform. Then he saw the man's hands appear, clutching the edge of the roof. A moment later his hooded head rose into view against the night sky! He was pulling himself up for a shot at close range!
Frank fought down a surge of panic. He had wriggled some distance away from the eaves. Now he must work his way back and try to overcome his assailant before the man could pull his gun.
Frank slithered toward him across the slippery shingles. By now the man had one leg up over the roof and was groping for the gun in his coat pocket.
"I won't be able to reach him in time!" Frank thought grimly.
Just then he heard steps racing up the stairway to the balcony.
The gunman heard the footsteps, too. He paused and looked down, then managed to extract the gun from his pocket. An instant later Frank saw his body jerk, and the man clutched the roof edge as if to brace himself.
Evidently the newcomer was pulling the gunman's other leg, trying to dislodge him! The hooded figure suddenly gave a tremendous heave upward and the next moment was free, sprawled full length on the roof. Frank by now was close enough to grab the man's coat sleeve.
The gunman threw up his arm and yanked it free. But the force of this action caused him to lose his grip completely! His gun arced through the air, hit the rear part of the roof, and bounced off. The man, meanwhile was rolling and slipping rapidly toward the edge.
Frank saw him clutch frantically for the gutter. The man caught it, hung suspended for a moment, then swung over to the drainpipe and slid down it to the ground.
"Frank! Are you all right?" It was Joe!
"I'm okay." As quickly as possible, Frank wriggled toward the stairway side of the roof and dropped safely onto the balcony platform.
The Hardys glanced over the railing. Below, the hooded figure was groping about hastily, trying to find his gun.
"Come on, Joe! Let's get him this time!" Frank urged, and the boys went bucketing down the stairs.
Hearing them, the man gave up his search and dashed off into the darkness. Their quarry was some distance ahead when Frank and Joe approached the inhabited part of Lucky Lode. But the town was so dimly lighted it was hard to keep the figure in view, except for his white hood.
The next moment the boys lost sight of him completely as he disappeared into the deep shadows around the general store. Nevertheless, Frank and Joe dashed in pursuit.
Reaching the store, they saw no one in front, so they ran to the back. The area was hidden in almost total darkness.
Suddenly Frank stiffened. "Did you hear something?" he muttered.
"Yes. Sounded like a door closing."
"Come on!"
The boys ran around to the front of the store. There were no lights showing. Joe grabbed the doorknob and shook it. The door was locked.
Frank knocked. The sound echoed loudly in the quiet of the deserted street. The boys waited for a few moments. When no one answered, Frank repeated his knock. He kept hammering on the door.
At last there was a response. From inside came the call, "Just a minute! Hold your horses!"
Presently a light showed, and a moment later Jim Burke came to the door, holding an oil lamp. He had pulled on a bathrobe over his long underwear.
"Well? What's all the excitement about?" From the look on his face, Burke was not pleased at being disturbed at so late an hour. Frank explained why they had roused him.
"Nope." Burke's expression was puzzled as he shook his head. "I haven't seen or heard anyone -except you two."
"Could the fellow we're after have slipped in your back door?" Joe asked.
"Not a chance," Burke replied. "I sleep right in the back room."
As Burke spoke, the front door suddenly burst open and Bob Dodge strode in out of the windy darkness.