For a perfect ensemble cast, actors' responsibilities are twofold: They each have to create a character that is distinct and three-dimensional, and they have to collaborate to create a fictional world that is, in most cases, as plausible as the one beyond the proscenium. If there's one bit of miscasting, the audience becomes conscious of a "performance" — and then the simulacrum crumbles. This was never the case in the Alliance Theatre Lab's unforgettable Savage in Limbo, in which director Adalberto Acevedo's five actors played together with the harmonic richness of a musical quintet with decades of experience. The setting was a broken-down bar where a handful of broken-down lives converged. These desperate, frantic, rootless barflies included Shira Abergel's 32-year-old virgin, Valentina Izarra's hooker-attired sparkplug, Curtis Belz's romantically scattered lunkhead, and Breeza Zeller's professional drunk, slumped in melancholy perpetuity over the bar. Christian Vandepas' barkeep presided over this carnival of lost souls with weary disillusionment while clinging onto a thread of hope that quietly unfurled. Collectively, these actors formed the emotional nucleus of a place in which no one ever wants to wind up, but it must have struck many viewers as painfully familiar.