Cultbox have released 10 very spoilery teasers from A Good Man Goes to War, so if you are avoiding spoilers then look away now.

• The Sontarans, Judoon, Silurians and Cybermen are all back.
  
• Simon Fisher-Becker returns as big blue Dorium Maldavar, last seen with River Song in 'The Pandorica Opens'.
  
• Karen Gillan has told Radio Times that "we discover who River Song really is" and "it's such a huge pay-off, I didn't see it coming".
  
• Rory's Roman costume returns.
  
• Frances Barber has told Total TV Guide that 'eye patch lady' Madame Kovarian is "involved in Amy's pregnancy - before and after the birth - and is in charge of a band of soldiers".
  
• The Sunday Times reveals that Amy's baby is named Melody.
  
• There's "a sort of Nazi state", according to guest star Charlie Baker, who also describes the story as "one of the darkest episodes ever".
  
• Catrin Stewart plays a character named Jenny. It's unknown if this is a regenerated incarnation of the 'Doctor's daughter' from Series 4, but - with a major character named Jen in the previous two-part story - it seems an unusual name choice if it's not her.
  
• The episode is "more disturbing than scary", according to Karen Gillan.
  
• Director Peter Hoar has summarised the episode as "a bit of a rollercoaster ride through all different times, space, everything".
  
• Hugh Bonneville is rumoured to return as 'The Curse Of The Black Spot''s Henry Avery, alongside Oscar Lloyd as Avery's son Toby.
  
• Part of the story is set in Jack the Ripper era London.