| Captain Scarlet And The Mysterons:|
|Season 1, Episode 5|
|Original Transmission||27 October 1967|
|Written by||Shane Rimmer|
|Directed by||Brian Burgess|
|Edited by||Harry MacDonald|
Spectrum Strikes Back
Shadow Of Fear
White As Snow
Avalanche is the 5th broadcast episode and 11th produced episode of the British television series Captain Scarlet And The Mysterons.
When the Mysterons target an outer space missile complex, it's up to Captain Scarlet and Lieutenant Green to keep it safe.
The Frost Line Outer Space Defence System is a network of missile complexes stretching 3,000 miles across North America, dedicated to protect Earth against extraterrestrial threats. When the Mysterons announce their intention to destroy key Frost Line bases, they kill Eddie, a maintenance engineer, by causing his truck to crash, and then reconstruct him. First targeting the Red Deer and Cariboo Bases, the Mysteron agent gets past the security at both stations and places devices inside their ventilation systems, leaving the air unbreathable and killing 250 men at Red Deer followed by 70 at Cariboo.
On Cloudbase, Colonel White orders Captain Scarlet and Lieutenant Green to investigate Red Deer and find out the Mysterons' exact method of attack. General Ward, the belligerent Frost Line commander, states that he will launch missiles against Mars if more bases are knocked out; White fears the Mysterons' response. At Red Deer, Scarlet and Green eventually discover that the personnel have suffocated not due to poisonous gas, but because all the oxygen in the air has been removed. Having requisitioned an SPV from a nearby hunter's lodge, the officers rush to the next base, Big Bear, only to discover that Eddie has already passed through and is now towards the Frost Line Command Centre.
After knocking out the sentry, who is under orders from Ward to prevent Spectrum from entering the base, Green extracts Eddie's oxygen-depletion device from the ventilation system before it can affect the air. Meanwhile, Scarlet chases Eddie in the SPV. The truck is carrying a large payload of liquid oxygen, some of which Eddie empties onto the path of the oncoming SPV to force Scarlet off the road.
Realising that Eddie may deliberately crash into his target to ignite the combustible substance and obliterate the Command Centre, Scarlet fires several shots from his gun into the snow-lined slope on one side of the track, opposite a sheer drop. This causes an avalanche which throws the truck over the edge, crashing down the rock face. The truck explodes, killing Eddie and saving the Command Centre.
- Captain Scarlet - Francis Matthews
- Captain Blue - Edward Bishop
- Colonel White - Donald Gray
- Lieutenant Green - Cy Grant
- Destiny Angel - Liz Morgan
- Voice of the Mysterons - Donald Gray
- General Ward - Paul Maxwell
- Eddie - Gary Files
- Sergeant Marshall - Charles Tingwell
- Lieutenant Burroughs - Jeremy Wilkin
- Trapper - Gary Files
- Red Deer Sentry Joe - Martin King
- Cariboo Sentry - Martin King
- Big Bear Sentry - Gary Files
- Radio - Jeremy Wilkin (not seen on screen, voice only)