T.G. Campbell

“Mr Locke...took a long, slender pick from the unrolled bag and, bending over slightly, inserted it into the lock. It was a steel-cased lock with a smooth, brass knob of around three inches wide and a brass plate around the singular keyhole. Mounted into the door frame was another steel fixture, forming the second half of the lock. Recognising the type of lock, Percy knew the key’s function was to throw the lock’s bolt into dead lock, thus securing the door. Such a design would also include an internal, smaller knob sliding back and forth, drawing back the bolt. A snib, jutting out from the case on the internal side of the door, could be compressed to keep the bolt in an open position, thus allowing one to open and close the door freely. “Do be so kind as to keep an eye out for the return of our friend the constable.” Locke pulled his pocket watch out with his other hand to glance upon it. “We have nine minutes.”
“This is breaking and entering!” Mr Maxwell cried, hurrying up the steps. “Miss Trent said such was forbidden by the Society.”
“Unless there is a sufficiently justifiable reason for doing so,” Mr Locke replied, inserting a second pick into the lower half of the lock. “The welfare of our client is a sufficiently justifiable reason; do you not think so, Mr Maxwell?”
“His welfare?” Mr Maxwell enquired, confused.
Miss Dexter, wholly fascinated by what the illusionist was doing, stepped closer still. She softly enquired, “Do you suspect some harm may have come to Mr Dorsey, Mr Locke?”
“I do not know but Mr Colby was very keen we should not speak with him. Furthermore, Miss Trent’s note stated her telephone conversation with Mr Dorsey was abruptly ended, by him, when another—angry—voice spoke,” Mr Locke explained. There was a sharp click as the bolt sprang back into the lock’s casing. Mr Locke smiled broadly.
“Our constable friend is back.” Mr Maxwell looked panic sticken. “It’s only been a minute.”
“Ah, that will be the Bow Street police station,” Locke replied as he turned the door knob. “Also, they tend to keep a closer eye upon the more affluent residences; greater targets for thieves, you know,” Mr Locke stated as he pushed the door open and ushered both Mr Maxwell and Miss Dexter inside. He’d just closed the door, after slipping in himself, when the constable reached the bottom of the steps and peered up at the porch. Mr Locke stood to the side of the door and watched as the constable, seemingly satisfied all was well, walked away. A glance down at the internal part of the lock confirmed Mr Locke’s earlier assumptions about it. His slender hand slid the smaller brass knob along to lock the bolt in place once more.”
― T.G. Campbell, The Case of the Curious Client