Petra initially imperils the group through the sheer power of her telepathic ability, but she also causes their eventual rescue by contacting the Sealand people over a vast distance and giving them an incentive to make the long journey to rescue her, Rosalind, and David. It is made disturbingly clear that the Sealand people are rather lacking in benevolence and only take the trouble to rescue the others because of their interest in Petra's incredibly developed talents.
Rosalind helps the group survive through her levelheadedness and dedication. As she tartly reminds David several times during the early part of their escape, she has planned and prepared for it far better than he has. She is also the first of the group to kill one of their pursuers.
The Sealand woman is the one who carries out the final rescue of the group, both by flying in to pick them up and by destroying the two groups of fighters who both intend to prevent the group's escape, though for different reasons: the Waknuk militia and the Fringes forces. She also presents a rationale for their killing off those who were hunting them.
Sophie, David's old friend banished to the Fringes for a minor deformity, helps the group escape by rescuing David after he is beaten and thrown out by the Spider Man, and by murdering the albino who is guarding Rosalind. She thus reunites and liberates the group while the Sealand forces are still too far away to do anything.