Ardwyck Fenn

In the novel The Mirror Crack'd from Side to Side, Ardwyck Fenn is an American man who was once wildly in love with Marina Gregg. He is in the movie business, and Hailey Preston describes him as a "very big shot in the television and moving picture world". He is a "dark man, heavily built" with "shrewd eyes behind thick glasses", and a "heavy jowl and chin".

Ardwyck attends the fete at Gossington Hall, arriving at the party together with Lola Brewster. Their arrival is a surprise to Marina and her husband, Jason Rudd, as they did not know that Ardwyck and Lola were in the country.

Ardwyck says that he had known Marina over a long period of years, off and on. At some point in the past, he had been wildly in love with her, and she had encouraged him only to turn him down later on. He used his influence to have her dropped from a picture she was making, but he says that this was purely a business transaction, as she was unsuitable for the role, and had conflict with the director. However, Marina viewed it as personal.

Later in the novel, Ardwyck tells Inspector Craddock that he had received a telephone call. The caller spoke in a whisper, and told him that they had seen him put the tablets in the glass on the day of the murder. The caller also said that he would soon be told what to do. He was not able to recognise the voice, but the caller had sneezed heavily before ringing off, so he knew that it was Ella Zielinsky, as he knew that she suffered from hay fever. He tells Craddock that he did not put tablets in anyone's glass. He thought that Ella had got hold of the wrong person on her first attempt at blackmail, and that it was possible that she was more successful later.

Portrayals
In the 1992 BBC adaptation, the character of Ardwyck Fenn is played by Constantine Gregory. There is no mention of his former feelings for Marina Gregg, and unlike the original, he does not turn up at the fete unannounced. He had been invited by Jason Rudd who also knew he would bring his girlfriend Lola Brewster along. Fenn has a larger role in this adaptation. He is set up as a plausible suspect for wanting to kill Marina Gregg. He is the producer working on the same filming project as Jason Rudd and Marina Gregg: the production of Elizabeth of Austria. Jason is the director and Marina has the lead role. Fenn had taken out a large insurance policy on Marina, insuring her for up to a third of the film production budget. The policy would pay out if for any reason Marina could not complete the film. In addition, Fenn's girlfriend Lola Brewster is a direct competitor with Marina for the lead role in the film and is all ready to step in should Marina be unable to continue. In this adaptation, Fenn and Lola are also invited for dinner at Gossington Hall. It is during this dinner that Ella Zielinsky dies after inhaling a poison which had been placed into her asthma inhaler. This plot addition was probably done to cast further suspicion on him.

In the 2010 ITV adaptation, the character is renamed "Vincent Hogg". He is a film journalist and not a film producer but he still has Lola Brewster as his girlfriend. Vincent is an ex-husband of Marina Gregg. In this adaptation, Vincent gate-crashed the garden party at Gossington Hall just like in the original novel. According to Hailey Preston, Marina Gregg was delighted to see him nonetheless. When Inspector Hewitt expressed incredulity at this, Preston told him that that is Hollywood. The part of Vincent Hogg is played by Martin Jarvis.