1 Stud: So, bridge foursome later. Can you take me to Strangways' place now?
1 Pleydell-Smith: Certainly.
2 {scene change: Strangways' cottage. It is a mess, with filing drawers open, furniture overturned, and a big blood stain on the floor.}
2 Pleydell-Smith: We left it how we found it. The blood matches his secretary's type.
3 Stud: Hmmm... nosebleed?
3 Pleydell-Smith: She was abducted! Probably killed!
4 Stud: Hey, who's the secret agent here? I'm supposed to be making the deductions.

2013-09-25 Rerun commentary: That's a lot of blood! Now that I think about it, the more blood, the funnier is Stud's assumption that it might have been a nosebleed.

It's interesting that in the 60s all they mention doing is matching the blood type of the stain with that of the missing secretary. (Pleydell-Smith's line in the second panel is verbatim from the movie Dr No.) Nowadays you'd have a CSI team all over it, doing DNA analysis and whatnot.