Dr Silver said she had gone to sleep at 5pm, after locking her study door, and had not woken up until Field-Marshal Mogau and Constable Ken woke her.

Yet a few minutes after Tracy had been murdered, Constable Ken was playing with the hot wax of the candle on the desk. This would have been impossible had not the candle been burning within a few minutes before he entered.

She must have been in her study to light the candle closer to the time before midnight… Closer than 5pm. She must have been lying about the fact of never leaving her room!