Sweet Revenge is a 1998 British comedy film written and directed by Malcolm Mowbray. The screenplay is based on the epic twopart play The Revengers Comedies by Alan Ayckbourn.
The plot, reminiscent of the Alfred Hitchcock film Strangers on a Train, focuses on two disparate characters. Conservative Henry Bell has been eased out of his job by condescending Bruce Tick, while wealthy and wildly eccentric Karen Knightly has been abandoned by her lover Anthony StaxtonBilling, who opted to return to his wife Imogen. Both are intent on committing suicide by leaping from the Tower Bridge in London. When neither succeeds, they strike a bargain whereby each agrees to exact revenge on behalf of the other, although Henry is less enthusiastic about the plan.Karen, disguised as a frumpy office temp, finds employment as an assistant to Tick and quickly derails his marriage by leading his wife Hilary to believe hes involved in an extramarital affair. Henry, meanwhile, is finding it difficult to keep his end of the bargain, since he has fallen in love with Imogen, the object of Karens revenge. Instead of planning her demise, he begins an affair with the beguiling woman. Henry learns that Anthony left Karen not for Imogen, but for beautician Daphne Teal, and he begins to suspect Karen is more of a villain than a victim. The woman proves to be a formidable foe when she realizes Henry may renege on their deal. ........
Source: Wikipedia