Andy Goddard, who directed the third season finale of “Downton Abbey,” will direct indie thriller “The Blunderer.”

Ted Hope and Killer Films’ Christine Vachon will produce, along with Sierra Pictures. Sierra will finance the film, which is adapted by Susan Boyd from Patricia Highsmith’s 1954 novel of the same, which she wrote in between “Strangers on a Train” and “The Talented Mr Ripley.”

Boyd optioned the novel with her husband William Boyd, the project’s executive producer.

“The Blunderer” follows a successful and handsome man who seems to have it all until the day his wife’s body is found at the bottom of a cliff. Under the intense scrutiny of the investigation, he commits one mistake after another until he finds his perfect life derailed.

Goddard is a British director who has directed multiple episodes of “Downton Abbey.” His short film “Little Sisters” was nominated for a BAFTA and won the Gold Hugo Award.

Kelly McCormick of Sierra/Affinity will oversee the production for the company.

Goddard is represented by Resolution, United Agents, and attorney Michael Schenkman. Susan Boyd is represented by Stephen Durbridge at The Agency.