John Simm – who returns in a two-part Christmas special as the Doctor's nemesis, The Master – has said that filming pal David Tennant's final episodes was really good fun.
"It'll be a brilliant send-off for David. Last time I did it it was such fun. It was wonderful to be asked back and to be in the very, very last one," he said.
He added that the two have yet to view the episodes but points out, "it was a great script."
"To go head-to-head with him was a real honour" said the actor – who made his first appearance in the series back in 2007 - of his friend David.
The Life on Mars star also revealed that one of the main reasons behind his decision to appear in the show was his young son Ryan. He admits that his other TV and film roles have been geared toward a more mature audience so his son has not been able to watch.
"It was a great opportunity to make my son proud," he said.
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