Temporada 4・DI Max Arnold and DS Layla Walsh return to uncover the deadly secrets and hidden motives behind the most powerful families and elite institutions in Chelsea. But as the cases grow darker, so do the personal challenges in their own lives.

Cinco amigos entran en las cuevas tailandesas de la Boca del Diablo, solo para descubrir que hay algo letal bajo el agua, cazándolos.