The novels emphasize Lady Blakeney's reddish gold hair, but she's played by brunette Elizabeth McGovern in this adaptation.
Bathtub Scene: Tony Dewhurst has a bath in public, with several girls washing him. He's a bit ashamed, and comments from the others suggest this might have lead to an off-screen Shower Of Love—and the loss of his virginity.
Canon Foreigner: As this is a loose adaptation of the books, quite a few characters are this, including members of the league.
Chuck Cunningham Syndrome: Suzanne de Tournay and Andrew Ffoulkes do not appear in series two; Andrew's role as Percy's lancer has been passed onto an orginal character, Sir William Wetherby.
Dies Wide Open: A member of the League, after being tortured by the Chauvelin's men. The Pimpernel does the obligatory eye-closing thing.
Fake Defector: Marguerite affects this in 'The Kidnapped King', staging a public estrangement from Sir Percy in order to return to France and get back into Chauvelin's confidence to inform for the League.
Ikea Weaponry: The Pimpernel has a dagger assembled from three pieces that fit into secret compartments in his boot.
The Pimpernel, an avid cricket player, delivers a bomb to a hard-to-reach area in the modern overarm manner. A companion suggests he should try that in his cricket games as a variant to the traditional underarm bowling. He says it'll never catch on. Either method of delivery was perfectly acceptable (although underarm was phased out in the late 19th century) until the 1980s, when underarm bowling was banned.
In the same episode, Percy hires a young unknown painter, Joseph Turner, to paint a landscape of his house and the surrounding gardens. Percy's friends are skeptical by the finished product, but Percy himself loves it and assures Turner that he's going to go places. This is Truth in Television; landscapes were relatively uncommon and it was in a large part Turner's work which elevated their status.
Kick the Dog: Chauvelin shoots the ALREADY badly injured Dewhurst to finish him off. It's not a Mercy Kill because of the likely fatal wound that he already has, it seems to be out of nothing but pure spite and anger that he wasn't able to catch Percy
Killing off the cute and endearing Tony Dewhurst in the very first episode? That's just cruel.
Helene de Rochambeau in "Valentine Gaultier". Shortly after she sees her lover Henri mortally wounded, she runs out to him, only to be shot herself.
Late-Arrival Spoiler: Not with the series so much, but with the original novel with regards to the Pimpernel's identity; from the start there's no attempt to conceal the fact that Sir Percy Blakeney is the Pimpernel.
Tricked-Out Shoes: The Pimpernel's boot with the secret compartments in the lining and heel.
Wall Slump: Tony dies this way. He's shot and badly wounded, but he manages to stand up, and he leans on a wall. Chauvelin shoots him later in the head. He just slumps down, and ends up half-sitting, half-lying and dead for good.