The Sontaran Stratagem spoilers Digtal spy

Wahey! A two-parter! An old enemy returns! It's hard to judge a story solely on the merits of its opening half, but 'The Sontaran Stratagem' is certainly more focussed than the meandering likes of 'Daleks in Manhattan' and 'Rise of the Cybermen'. Anyway, the full, mostly positive review will be online straight after Saturday's episode, so in the meantime here are a few spoilers to keep you going - with two red herrings chucked into the mix:

Both the Ood and the Adipose make a surprise appearance.

Wilf has been put on a macrobiotic diet.

When The Doctor first reunites with Martha and learns that she is now a Doctor, he sings the chorus from the song 'Dr Jones' by Aqua to her. She is not impressed and calls him 'Mr Cheese'.

The Sontarans discuss their involvement in the Time War.

The Doctor berates a child genius over his decision not to deploy the conditional clause in conversation.

A Sontaran leader is called a 'baked potato' by a human.

The Doctor displays his squash skills - much to the annoyance of a Sontaran. It's not just cricket the Time Lord excels at.

Someone experiences death by Sat Nav.

Rose Tyler is briefly glimpsed for a couple of seconds when she emerges from the slime after being cloned by the Sontarans.Thank you Digital spy