Endeavour2012

DC Endeavour Morse:
Strange, there's a blackboard there. Could you...? [Strange gets the board] Each element is assigned a symbol: Typically an abbreviation of its name together with a unique one or two-digit atomic number. Can you write these down as I call then off? [Strange cleans the board and writes the elements on the board as Morse calls them out] So, 74 gives us Tungsten. 17, Chlorine. 18, Argon. 19, Potassium. The elements spell out a name.

Chief Superintendent Bright:
[looking at the first letters of the elements] T.C.A.P Tucap?

DC Endeavour Morse:
No, not quite, sir, but you're on the right lines.

[Morse walks over to the blackboard and Strange gives him the chalk]

DC Endeavour Morse:
Um, the chemical symbol for Tungsten isn't Tu as you might expect. It's W from the German Wolframite. And Potassium isn't P as you might expect but K after the Latin Kalium. Taken together they're Tungsten...

[close-ups of these four elements and their chemical symbols in the Periodic Table are seen as Morse writes the chemical symbol W]

DC Endeavour Morse:
...Chorine...

[Morse writes the chemical symbol CL on the blackboard]

DC Endeavour Morse:
...Argon...

[Morse writes the chemical symbol AR on the blackboard]

DC Endeavour Morse:
...and Potassium.

[Morse writes the chemical symbol K on the blackboard]

DC Endeavour Morse:
W-C-L-A-R-K. Wallace Clark.

[flashbacks of Wallace Clark committing the murders are seen with close-ups of the Periodic Table]

Chief Superintendent Bright:
[almost speechless] Good grief.

DI Fred Thursday:
Derek's father.

Chief Superintendent Bright:
But there's nothing to say he even knew the vicar.

DC Endeavour Morse:
Ivy Clark, sir. Wallace's wife is buried in the churchyard. [Ivy's Clark's tombstone is seen] The next plot but one to Lady Daphne Sloan. Reverend Monkford performed the service.

PC Jim Strange:
[laughs] Bloody hell, matey. That's...

DI Fred Thursday:
[stunned and impressed] Elementary.