The three doors

Marty split off from the other three, at the base of an exposed metal staircase on the outside of the ark. To everyone's sheer amazement, he found Matthias, Joey and Rose who were members of the other 12 travellers. Joey was very well researched in matters pertaining to the civilization and was the person who decided that the group should be split in a certain way. Armand was still suffering from the bubbly rash, so therefore he, Edith and Paula were to return to the central core following Joey's instructions.