A new Monte Carlo move for polymer simulations is presented. The "wormhole" move is build out of reptation steps and allows a polymer to reptate through a hole in space; it is able to completely displace a polymer in time N-2 (with N the polymer length) even at high density. This move can be used in a similar way as configurational bias; in particular, it allows grand canonical moves, it is applicable to copolymers, and can be extended to branched polymers. The main advantage is speed, since it is exponentially faster in N than configurational bias, but is also easier to program.