To Hell and Back

To Hell and Back (or THAB) is a crossover series primarily between Battlestar Galactica: 2003 and Gundam SEED/SEED Destiny. However, via use of a modified Faster-Then-Light drive known as the Trans-Universal FTL Drive, other universes (Gundam 00, StarCraft and others) have been crossed over.

Original Version
To Hell and Back was originally posted in May 2009, and since then, 7 stories have been published. However, the latest, Loki's Fall, has been abandoned, as the author has chosen to rewrite the entire series in what has been titled the Ultimate Rewrites Edition. (URE)

THAB URE
To Hell and Back: Ultimate Rewrites Edition (or THAB URE) was published on May 27th, 2013, and was the first rewritten THAB story to conform more to the recently released Blood and Chrome. Changes from the original include: To compare, THAB URE is akin to Rebuild of Evangelion in that it has the same basic plot, but a different ending and different characters.
 * A different timeframe (the original started in late Season 2.5 while THAB URE starts after the events of Tigh Me Up, Tigh Me Down)
 * More elements from BSG: 2003 (THAB was much lighter then   BSG: 2003   while THAB URE is just as dark)
 * Features more original ships (i.e, the Spitfire and Hermes-Class support ships)
 * One of the main characters (Major, then promoted to Colonel Ronald Pinkerton) is no longer the main antagonist, but a supporting progagonist.

Colonial Corps of Engineers
A key feature in both THAB timelines is the Colonial Corps of Engineers, (CCE) based on the real-world organizations DARPA and the United States Army Corps of Engineers. In THAB, the CCE was founded after was war under Rear Admiral Zeus Avalonia with his daughter Nova and then-Captain Ronald Pinkerton as chief designer. The CCE developed and built all of the regular Fleet's ships, and built even more for themselves to support the regular forces. Due to not linking communications into their networks, the entire CCE fleet survived and would later support the Fleet that Galactica (and later Pegasus) was escorting to Earth.

In THAB URE, the CCE's story is almost the same, but was founded during the war. As wth the original, Zeus Avalonia is head of the Corps, but Pinkerton's title has changed from chief designer to field marshal, responsible for all CCE projects.

Basic Plot
No matter what version, the basic plot and starting point is the same: on Earth, during the Battle of Berlin in Gundam SEED Destiny. The Archangel, Minerva and a large part of the city are sent across the galaxy, meeting the fleeing Colonial Fleet, which they help defend and guide to Earth.

The similarities end there, however. In the original, the Earth ships are sent to the Colonial Fleet via an insane time traveling Colonel Pinkerton, whose plan of altering the timeline was stopped by Colonial forces. In THAB URE, the FTL event was natural.

Related material
Galactica (D31)

Pegasus (D31)