 Trip thinks he s found a way to get the warp drive to maintain high speeds for a longer time. Something goes terribly wrong however when Enterprise enters a polaric field with nucleonic particles that attach themselves to the hull and will destroy Enterprise in time. Trip is installing the new drive and due to the field a warp manifold explodes, leaving him in a coma and Enterprise without a functional warp drive. Phlox isn t too happy about Trip s prospects and sees only one solution. He has a Lyssarian desert larvae that can clone Trip and make a fast-growing symbiote of him with a lifespan of only fifteen days. Phlox can then extract brain tissue when it has grown to Trip s age, after which the symbiote could lead a normal, albeit short, life. Archer agrees with the procedure, but the symbiote, Sim, has serious doubts about the operation when he finds out Phlox was wrong and the procedure will kill him. Meanwhile the nucleonic particles are becoming a real problem.