Why?

Based on the book "UFO Crash at Roswell" by Kevin Randle and Donald Schmitt, Roswell follows the attempts of Major Jesse Marcel to discover the truth about strange debris found on a local rancher's field in July of 1947. Told by his superiors that what he has found is nothing more than a downed weather balloon, Marcel maintains his military duty until the weight of the truth, however out of this world it may be, forces him to piece together what really occurred.

On a trip to Colombia, a group of college students encounter a fifty-foot boa constrictor, hungry for blood.

A psychiatrist becomes the new Sorcerer Supreme of the Earth in order to battle an evil Sorceress from the past.

The Doctor has retired to 1892 London. Despite the protests of his allies, he is determined to keep out of mankind's affairs. However, a governess named Clara has stumbled upon a plot which only the Doctor can unravel, involving the death of her predecessor in ice and the sinister Dr. Simeon, who controls monsters made of sentient snow. And there is another mystery afoot: Clara is the spitting image of Oswin Oswald, whom the Doctor saw die in the Dalek asylum...

A meeting in a London bus with jewel thief Lady Christina takes a turn for the worse for the Doctor when the bus takes a detour to a desert-like planet, where the deadly Swarm awaits.