Thorndyke is so very punctilious about his engagements." The mystery was solved, when we reached the landing, by a slip of paper fixed by a tack on the iron-bound "oak." "A note for P.B.is on the table," was the laconic message: on reading which I inserted my key, swung the heavy door outward, and opened the lighter inner door.

The note was lying on the table and I brought it out to the landing to read by the light of the staircase lamp.
"Apologise to our friends," it ran, "for the slight change of programme.
Norbury is anxious that I should get my experiments over before the Director returns, so as to save discussion.

He has asked me to begin to-night and says he will see Mr.and Miss Bellingham here, at the Museum.

Please bring them along at once.

The hall porters are instructed to admit you and bring you to us.