Generic tracking of multiple apparent horizons with level flow

We report the development of the first apparent horizon locator capable of finding multiple apparent horizons in a ``generic'' numerical black hole spacetime. We use a level-flow method which, starting from a single arbitrary initial guess surface, can undergo topology changes as it flows towards disjoint apparent horizons. The level flow method has two advantages: (1) The solution is independent of changes in the initial guess and (2) the solution can have multiple components. We illustrate our method of locating apparent horizons in a short Kerr-Schild binary black hole grazing collision.