Penny started to say that she did not know. Just then Mattie Williams’ partner came in the other door.

“Hi, Sam!” the stranger greeted him. “I’ve got the car parked around back. Are you ready to put on that tire?”

Sam frowned, darting a quick glance at the two girls.

“Oh, the one I patched for you!” he returned. “Sure, it’s fixed. Drive your car in the back entrance and I’ll take care of it.”

Both men went out into the main part of the garage. Just beyond the door they paused for a whispered conference, then separated.

“Shall we go?” inquired Louise, glancing at her chum.

“Not just yet,” replied Penny. “I’m curious to see that patched tire. Let’s kill a little more time here.”

Pretending to warm themselves by the stove, they waited ten minutes. Then, without attracting attention, they sauntered out onto the main garage floor. Mattie Williams was busy washing a car and did not see them.

The garage workroom was divided into sections, separated by a double door which was closed. Penny strolled over and pushed it open just enough to see through the crack.

Sam Burkholder was working on the stranger’s car. He had removed an old tire and wheel, and was replacing it with one whose tread appeared new.