Rupert Graves has joined the cast of BBC1 drama Last Tango in Halifax.
Graves, known to millions of Sherlock fans for his role as the well-meaning but not necessarily brilliantly deductive Inspector Greg Lestrade, will begin filming his scenes for series three shortly.
He plays Gary Jackson, who is first seen going on a date with Alan’s daughter Gillian (Nicola Walker) but “may not be all he seems”, according to producers.
Derek Jacobi and Anne Reid return as aging newlyweds Alan and Celia, who have already experienced various highs and lows in the first two series, including Alan’s recovery from a heart attack and their own wedding.
Series three, due in the autumn, promises to test the couple further when “Alan’s world is shaken by someone from his past, causing a rift between him and his beloved Celia” according to a BBC statement.
The second season, which aired on BBC1 last year, regularly attracted more than seven million viewers.
Writer Sally Wainwright said: “I’m thrilled that we’re going into a third series with really exciting new story lines that move Celia and Alan’s relationship forward with hopefully the same mix of gusto, comedy and drama.”
RED executive producer Nicola Shindler added: “We’re so excited to get everyone back together for the third series of our multi-award winning show and we’re thrilled Rupert’s joined our stellar cast. The continued support and success of this much-loved drama is testament to Sally’s warm and sincere scripts and we can’t wait to show fans what we have in store for the new series.”