Did she jumpor was she pushed? The Retired Detectives have a theory. Now they just need the evidence. The brand-new Shimmering Sands retirement community is a beachfront paradiseuntil realtor Jessie Beckton plunges to her death from the penthouse suite shes selling. When the cops rule out foul play, the Retired Detectives agree to step in. Theyre certain Jessie was murderedbut how can they prove it when the apartment was locked from the inside?As the gang pursue their investigation, a host of potential suspects emerge who all have secrets to hide. But just as they seem to be closing in on a culprit, a shocking second murder sends them back to square one.Meanwhile, former CSI Lizzies marriage to ex-DCI Philip suffers a fateful blow. And their partners in crime-solving, Rick and Moira, find their new romance tested when a mystery woman from Ricks past appearswith a child in tow.The team must put aside their differences and join forces with a former adversary if theyre to solve the case. But in a deadly game of cat-and-mouse, can they lure the killer into the open before one of them pays the ultimate price?