"Mrs Wilberforce..? I understand you have rooms to let."

And so we are introduced to the sinister and mysterious Professor Marcus, performed with brio by Alec Guinness as a sort of unhinged Alastair Sim grotesque, in Alexander McKendrick's sublime 1955 Ealing comedy The Ladykillers.

The film – described by McKendrick as a film about Britain in subsidence - was the first major film role for Peter Sellers, after a string of low budget and mostly forgettable little comedies. Although his role as the aging Ted and spiv Harry Robinson is very much a supporting one, it did get him noticed, and his subsequent career in films grew steadily with a BAFTA for Best Actor five years later and international super-stardom in less than a decade.

Alongside Guinness and Sellers are the splendidly menacing Herbert Lom as Louis Harvey, Cecil Parker as Major Courtney and Danny Green as 'One Round', posing as members of a string quintet who have robbery on their minds. Playing the role of her lifetime as the titular 'lady' is Katie Johnson in her penultimate film as Mrs Wilberforce, a performance which won her a BAFTA.

Joining Tyler to talk about the film is Graeme Lindsay-Foot, for whom this film remains one of his all-time favourites after having first seen it as a teenager. Together they break down the film from its earliest beginnings, as fragments of a dream occurring to the writer William Rose, to the production process. casting, plot and - yes- there WILL be spoilers. Fans of Frankie Howerd are duly warned that he comes in for a bit of flack.

We answer these questions:

WHY did Herbert Lom wear a hat throughout the film?

WHO was the inspiration for the look of Professor Marcus?

WHAT bits of the film were cut out, causing Sellers much annoyance?

HOW did Sellers commemorate the film in the form of a gift for cast and crew?

WHERE was Mrs Wilberforce's lopsided old house actually situated in London?

... And much more!