We study the effect of a first-order phase transition in a confining SU(N) dark sector with heavy dark quarks. The baryons of this sector are the dark matter candidate. During the confinement phase transition, the heavy quarks are trapped inside isolated, contracting pockets of the deconfined phase, giving rise to a second stage of annihilation that dramatically suppresses the dark quark abundance. The surviving abundance is determined by the local accidental asymmetry in each pocket. The correct dark matter abundance is obtained for O(1−100) PeV dark quarks, well above the naive unitarity bound. After introducing the general framework, I will discuss implications and opportunities to search for such heavy dark states.