ITV 1′s ‘The Poison Tree’ Gets An Intriguing New Trailer [Video] December 6, 2012 ITV, News The past is a character unto itself in ITV 1′s trailer for their upcoming two-part drama The Poison Tree, based on the novel by Erin Kelly. Flashing between the present and the long summer of 1999, The Poison Tree begins with the reunion of Karen Clarke (MyAnna Buring) and Rex (Matthew Goode), who have been separated for 11 years while Rex served time in prison. However, his happy homecoming is short lived, as Karen begins to receive unwelcome reminders of the past. In addition to Buring and Goode, the series stars Ophelia Lovibond (No Strings Attached) as the third member of the trio at the heart of the dark events that landed Rex in prison. The Poison Tree premieres Monday, December 10th at 9:00pm on ITV 1 in the UK.