All the episodes and extras from stories featuring the Sontarans are out in this box set including.

The Invasion of Time

After a meeting in space with a group of unseen aliens the Doctor returns to Gallifrey and claims the presidency of the Time Lords. Leela meanwhile tries to work out why he is behaving out of character. At his induction, the Doctor is 'crowned' with a device giving him access to the Matrix. He then arranges for the transduction barriers around Gallifrey to be put out of action by K9. When this is done, his alien 'friends' materialise. They are telepathic invaders called Vardans...

The Two Doctors

When the Doctor (Colin Baker) lands on a space station in the Third Zone, he suspects he's been there before and when he discovers his old assistant - Jamie - he's certain. Accompanied by Jamie and his present assistant Peri, the Doctor follows himself (Patrick Troughton) to 20th Century Seville. There he discovers his old enemeies, the Sontarans, about to dissect him in a genetic operation. But just why are they operating on the Doctor? And how will their findings aid their enslavement of the universe? Deadly questions to which the Doctors must find answers in order to escape their own excruciating death...

The Sontaran Experiment

Arriving on a desolate and windswept Earth the Doctor starts realigning the transmat refractors while Sarah and Harry go off to explore. Harry slips and falls into a pit and Sarah runs back to the Doctor to get help. The Doctor, however, has been captured by a trio of shipwrecked Galsec space travellers who were lured to Earth by a phoney distress call. Sarah, unable to find the Doctor, makes friends with a fourth space traveller, Roth, who tells her of the alien in the rocks who is experimenting on them.

The Time Warrior

His spaceship crippled in an inter-stellar battle, the Sontaran warrior, Linx, is forced to crash land on Earth. He arrives in the Middle Ages, a time too primitive to provide the technology he needs to repair his ship. Allaying himself with the local robber chief, Linx uses his powers to 'borrow' scientists and equipment from tentieth-century Earth. The Doctor tracks down the missing scientists and journeys into the past to save them. But can he defeat the ruthless Linx and his savage human allies before the course of human history is changed forever?