'No; he has a latchkey, and he let himself in.'

'实在不知道。他有一把弹簧锁的钥匙，他自己会开进来的。'

There was a spring lock on the door.

有一把弹簧锁。

That latch is a bit stubborn, but I'll take care of it.

那道弹簧锁很难处理 但我会处理好的。

Mrs. Saunders, the caretaker, was about to leave, but she had no hesitation in admitting us, for the door shut with a spring lock, and Holmes promised to see that all was safe before we left.

桑德斯夫正要离开， 但她毫不犹豫地接纳了我们， 因为是用弹簧锁关的， 福斯答应在我们离开之前确保一切安全。