Colin McNabb

In the novel Hickory Dickory Dock, Colin McNabb is a resident at the hostel in Hickory Road owned by Christina Nicoletis. He is doing post-graduate studies in psychiatry. A fellow resident Celia Austin was attracted to him but could not get him to show any interest. She then pretended to have kleptomania by stealing a number of random objects from the other residents. This had the intended effect. When Celia later confessed to the thefts, Colin became interested in her as "a case" and defended her actions to others and offered to take care of her. He later announced that they were engaged to be married, but she was murdered shortly thereafter.

Portrayals
In the 1995 ITV TV film adaptation, Colin McNabb is portrayed by Gilbert Martin. He has a significantly larger role here. His attraction to Celia as "a case" is depicted faithfully although in this adaptation he never goes as far as getting engaged. To the other residents he also made the boast that he knew how to commit the perfect murder--it have to be a killing with absolutely no motive. "Take away the motive" and criminals "become invisible" he claimed. He also boasted that he knew how to get hold of a quantity of poison and made a bet to this effect. He then accomplished the feat by dressing up in a white coat, wearing a stethoscope which he had stolen from a medical student Len Bateson and then casually strolling into a hospital pharmacy and helping himself to a bottle of morphine tartrate. As he told Poirot and the police later, nobody notices a doctor in the pharmacy. However when Celia Austin was found poisoned by morphine, things began to look bad for him. He insisted that he had no reason to kill Celia, whereupon Poirot reminded him of his boast about the perfect murder with no motive. Japp later found a bottle of morphine under the floorboards in his room, this was enough and Colin was arrested. In the original novel, the bet and the subsequent theft of the morphine was done by Nigel Chapman.

There is no parallel character for Colin McNabb in Pension Vanilos, the TV film adaptation of the novel by France Télévisions. The hostel there had fewer residents. As a result, the Celia Austin parallel was in love with Jean-Baptiste Millet who in this adaptation is the parallel of Nigel Chapman. It is also never explained why she stole objects from the other students, since Jean-Baptiste did not study psychiatry.