I shudder at the thought - this Colonel clever man. Difficult enough to shadow if he does not suspect. Impossible if he leaps on guard.”

“Then what do you suggest?” asked the girl.

“Let Li Gung, unknowing, be watched. If he seeks to proceed beyond Honolulu, rough hands will restrain him. Otherwise we permit him to lie, like winter overcoat in closet during heated term.” Chan turned to Barry Kirk. “You are taking me back to hotel?”

“I am not,” smiled Kirk. “No more hotel for you. If you’re going to look into this little puzzle, the place for you is the Kirk Building, where the matter originated. Don’t you say so, Miss Morrow?”

“That’s awfully kind of you,” said the girl.

“Not at all. It’s painfully lonesome up where the fog begins without at least one guest. I’m all out of visitors at the moment - er - ah - I mean Mr. Chan will be doing me a real favor.” He turned to Charlie. “You shall have Sir Frederic’s room,” he added.

Chan shrugged. “I can never repay such goodness. Why attempt it?”

“Let’s go to my office, first of all,” Miss Morrow said. “I want the district attorney to meet Mr. Chan. We must all be friends - at the start, anyhow.”

“Anywhere you say,” Kirk agreed, and headed the car up Market Street, to Kearny. He remained in the roadster, while the girl and Charlie went up to the district attorney’s offices. When they entered that gentleman’s private room, they found Captain Flannery already on the scene.

“Mr. Trant - I’ve good news for you,” the girl began. “Oh - good morning, Captain.”

Flannery’s Irish eyes were not precisely smiling as they rested on Charlie Chan. “What’s this, Sergeant?” he growled. “I thought you were off for Honolulu at twelve?”

Chan grinned. “You will be delighted to learn that my plans are changed. Miss Morrow has persuaded me to remain here and add my minute brain power to your famous capacity in same line.”

“Is that so?” mumbled Flannery.

“Yes - isn’t it splendid?” cried the girl. “Mr. Chan is going to help us.” She turned to her chief. “You must give him a temporary appointment as a sort of guest detective connected with this office.”

Trant smiled. “Wouldn’t that be a bit irregular?” he asked.

“Impossible,” said Flannery firmly.

“Not at all,” persisted the girl.