Doctor Who returns to BBC One this weekend for a sixth series, starring Matt Smith as the Eleventh Doctor alongside Karen Gillan and Arthur Darvill as his companions Amy and Rory.

Episode 1, ‘The Impossible Astronaut’, airs at 6pm on Saturday 23rd April.

Four envelopes, numbered 2, 3 and 4, each containing a date, time and map reference, unsigned, but TARDIS blue. Who sent them? And who received the missing number one? This strange summons reunites the Doctor, Amy, Rory and River Song in the middle of the Utah desert and unveils a terrible secret the Doctor’s friends must never reveal to him.

> Order the Series 6 Part 1 DVD on Amazon.

> Order the Series 6 Part 1 Blu-ray on Amazon.

We’ve picked out ten teasing lines of dialogue from the episode…

» “You better get down here, Sir. She’s doing it again. River Song… she’s packing.”

» “Whatever happens now, you don’t interfere – clear?”

» “If we’re going to do this, let’s do it properly.”

» “This is cold. Even by your standards, this is cold.”

» “Who’s Jim the fish?”

» “Don’t play games with me – don’t ever, ever think you’re capable of that.”

» “Very much not in need of getting shot!”

» “Don’t worry, I’m quite the screamer.”

» “I live for the days when I see him. But I know that every time I do, he’ll be one step further away.”

» “I had something I wanted to tell him, but stuff always gets in the way.”