"He hasn't heard my story because I just remembered. Joe went Here he comes now."

As Joe came in, he asked, "Frank, how did you make out?"

"Great! Listen! Taffy Marr is working at Bickford's!"

"No kidding?"

"It's straight. I got the tip from Shorty, the prisoner," Frank answered. "And listen to this. Aunt Gertrude saw Marr with Chris in Gresham! While I remove my disguise, will you call Chief Collig and tell him this ?".

"Okay, and let's go down and watch the fun when Marr is arrested," Joe urged.

It took Frank only five minutes to take off his costume and makeup. Since Mrs Hardy and Aunt Gertrude planned to leave the house, Joe put Mr Wright's invention in the tyre well of the boys' car. Then he and Frank rode downtown in the convertible. When they reached Bickford's, there was a good-sized crowd in front of the jewellery store.

"What's going on?" Joe asked a bystander.

"Don't know. An attempted holdup, I guess. Police arrived and circled the building. We've been waiting for them to bring somebody out."

A siren began to wail and seconds later an ambulance raced up the street. It stopped in front of the jewellery store. A hush fell over the crowd as they waited for the victim to be brought out. Would it be Taffy Marr, or a policeman who had gone in to arrest him or would it be the shop owner?

A stretcher was carried in and a little later it was brought out bearing a man. His eyes were closed and his face ghostly white.

"It's Mr Bickford!" Joe exclaimed.

Instantly the boys pushed through the crowd and rushed up to an officer just emerging from the store. He knew the Hardys and beckoned to them.

"We were just a little too late arriving to catch Marr," he said. "Marr must have attacked Mr Bickford and cleaned the place out before he skipped."

"A complete haul, you mean?" Joe asked.

"Took everything."

"How bad is Mr Bickford?" Frank inquired.

The officer shrugged. "He's unconscious and his pulse is weak."

Joe spluttered angrily, "If I get my hands on Marr, I'll-I'll"

"It's going to be tough tracking him down," Frank predicted. "I'll bet by this time he's wearing a disguise and has already left town."

Joe snapped his fingers. "If he owns a suitcase full of disguises, he probably went back to wherever he's living to pick them up. Officer, have you any idea where he's living?"

"No, but our men are questioning people in the neighbourhood."

As the ambulance pulled away, the boys asked permission to check out the jewellery shop for a clue to Marr's address.

The officer smiled. "Go ahead. You fellows may manage to pick up a lead before the police check. I'm to stay on duty outside so take all the time you want."

Frank told his brother he was sure Mr Bickford would have some kind of record concerning his a.s.sistant.

"No doubt they will be under an a.s.sumed name, but let's have a look."

The boys found a drawer full of papers. Under them was an account book. They read each name listed in the book and at last came to one with recent, regular notations of payments.

"This might be him," Frank observed. "Ray Stokeley, 49 New Street."

"It's worth following," Joe said.

Frank and Joe briefly told the officer on duty they might have a lead and dashed off to their car. They soon reached New Street, where most of the oldfashioned houses had "Rooms for Rent" signs in windows. Number 49 was a large run-down mansion, set far back from the street.

Frank and Joe climbed the high steps and rang the bell. A neatly dressed, middle-aged woman opened the door.

"Is Mr Stokeley at home?" Frank inquired.

"No, he left-moved out, not ten minutes ago."

The woman started to close the door, but Frank, smiling at her, said, "We think he's the man we're looking for, but we're not sure. Would you mind describing Mr Stokeley for us?"

Her description fitted Marr. Frank nodded. "He's our man. Do you know where he went?"

There was no answer for a few seconds, then the woman said jokingly, "Who are you? Boy detectives?"

"Yes," Joe replied promptly, "and Mr Stokeley is wanted by the FBI and police. You'd be doing them a great favour if you tell us ail you know."

"Oh!" she gasped. "I know very little about Mr Stokeley. But I did hear part of a phone call he made early this morning. He said, 'Then to the airport.' Does that help you?"

"Yes indeed. Thanks," Frank answered as he and Joe raced down the steps.

They arrived at the airport in record time. As they rushed through the terminal lobby, the boys caught sight of Cole Weber, the pilot, looking at the antique aircraft and waved.

"If Marr's wearing a disguise, how can we spot him?" Frank said.

Joe was staring at a man with grey hair, moustache, and a beard. He stood near a counter, talking to a redhaired fellow.

"Frank, took! That guy the grey-haired man's talking to looks like one of the kidnappers!"

"Sure?"

"Positive! And I'll bet Grey Beard is Taffy Marr!"

The men turned and went out to the field. Frank and Joe followed. The suspects started running towards a small white single-engine plane that was ready for take-off. They climbed aboard quickly.

"Now what'll we do?" Frank asked.

"Only one thing we can do," Joe replied. "Follow them!"

CHAPTER XV.

Pursuit "BUT how can we follow Marr?" Frank asked. "If only Dad's plane were here, we could do it easily."

He was referring to the sleek, six-seater aircraft owned by their father. However, Mr Hardy and his pilot Jack Wayne had flown it to California with Mr Wright.

"Keep an eye on that white bird," Joe ordered. "I'll run into the administration building and telephone Agent Keith. Then I'll go to Manson's Charter Service and see if we can rent a plane."

"You'd better make it quick!" Frank warned.

Joe rushed to a phone booth inside the administration building and dialled Keith's code number. It took only seconds to make the connection.

"Agent Mallett speaking!" crackled a deep, firm voice.

"This is Joe Hardy. Is Agent Keith there?"

"No, but he should be back in a few minutes."

"Can't wait!" Joe declared. "Tell him my brother and I are trailing a man we're sure is Taffy Marr. We're at Bayport field. The suspect and another man are about to take off in a white single-engine job. We'll try to follow them. I'll keep you posted!"

"Good work!" Mallett said. "Try to get the registration number of their plane so that we can trace its owner."

"Right!"

Joe hung up quickly and went directly to one of the terminal's counters. Behind it stood a plumpish, pleasant-faced man. On the wall hung a sign which read MANSON'S CHARTER SERVICE.

"Well, if it isn't Joe Hardy!" the man declared.

"h.e.l.lo, Mr Manson."

"Where have you been keeping yourself? Haven't seen you around the airport lately."

"We've been sleuthing," Joe answered with a wink. "I'd like to charter one of your planes right away!"

"Gosh, Joe, I'm sorry, but all my aircraft are out on flights," Manson said apologetically.

"Haven't had such a busy day in months."

Suddenly Joe had an idea. How about Cole Weber? He rushed off and in a few moments found the lanky owner of an antique plane.

"Nice to see you again," the pilot greeted him. "What's the rush?"

"I'm looking for a ride."

"You've come to the right man. I'll be glad to fly you wherever you want to go," Weber told him.

Joe drew the pilot aside and in a low voice briefly explained the situation to him. "Could your aircraft keep up with a fast plane?"

Frank rushed into the lobby. "Marr and his friend are getting ready to take off!" he exclaimed.

Followed by his brother and Weber, Joe ran to a window overlooking the field. They spotted the small, single-engine plane taxiing to the active runway for take-off: Frank jotted down the registration number.

"Is this the one you want to follow?" Weber commented. "That type isn't too fast. I'm sure I could keep up with it."

"Great!" said Frank.

"We'll have to make it snappy!" Joe urged.

"Maybe not," Weber answered. "There's a long line of planes waiting for take-off clearance. It'll be at least ten minutes before those men can clear ground. That'll give me time to telephone the control tower.

Since my plane is not equipped with radio, they'll have to okay me for take-off by flashing a green light."

Frank said, "How about warning the control tower not to let Marr take off?"

Weber looked surprised. "Are you completely sure that one of those pa.s.sengers is Marr?" he asked.

"Well, no, we're not," Joe confessed.

"Then I think we'd better not make such a request," the pilot advised. "All of us might get into trouble."

The boys nodded and Joe said, "We'll just make a chase of it."

Weber went off but soon returned. "Everything's set," he said. "And we're in luck! The control-tower boys are going to let us take off from the gra.s.s shoulder of Runway Six. It means we won't have to wait in line for clearance. Chances are we'll be off the ground ahead of your friends."

The Hardys followed the pilot to his orange-and-white biplane. He drew three parachutes from the baggage compartment and instructed Frank and Joe to put them on while he fastened his own.

"Climb aboard!" he said, The boys seated themselves side by side in the front c.o.c.kpit. Weber signalled a mechanic to help start the engine, then jumped into the rear c.o.c.kpit.

"Brakes on! Contact!" the mechanic shouted.

"Brakes on! Contact!" Weber replied.

With a single whirl of the propeller, the engine roared to life. The boys were so thrilled by the chance to fly in an old biplane that for a moment they had almost dismissed Taffy Marr from their minds.

Weber began to glide his wood-and-fabric craft down the runway. Nearing Runway Six, he veered on to the gra.s.s shoulder which paralleled it.

"All set?" the boys heard him shout over the sound of the engine.

"All set!" Frank and Joe answered.

Their pilot pivoted the craft round and pointed its nose into the wind. Shortly a bright disc of' green light beamed from the control tower. The engine emitted a loud, steady roar as Weber advanced the throttle.

The plane bounced across the gra.s.s surface, then cleared it. Frank looked down and spotted Marr's craft just taxiing into position for take-off.

After reaching a couple of thousand feet, Weber circled the airport. He and the Hardys watched intently as the other plane sped down the runway and became airborne far below them.

Weber manoeuvred his craft at a safe distance behind Marr's plane, which was now heading on a north-easterly course.