Michael Dibdin Dead Lagoon
When his American ex-girlfriend puts him in contact with the family of a missing American millionaire who are determined to establish his whereabouts )dead or alive) and are willing to pay whoever does the leg work all Aurelio Zen needs is a pretext to take himself off to Venice, which is where we find him at the start of Dead Lagoon.
Officially, Zen is back in town to investigate complaints made by an elderly contessa widely believed to be mad. Naturally, her allegations that Swamp-dwellers are invading her house are held to be evidence of a mind unhinged by the disappearance of her daughter towards the end of World War Two.
Zen’s return to Venice coincides with political turmoil as a separatist movement gathers strength contrasting the city's current state with former glories and suggesting that things would be far better in an autonomous Venetian republic.
His investigations lead him into conflict with a charismatic local rising politician and a childhood friend and matters are further complicated when Zen, his passion for Tania cooling rapidly, and falls for the attractive estranged wife of the separatist movement's leader.
There’s an extra complication when a corrupt police officer is found murdered in one of the city's noisome pozzi neri (black wells, the septic tanks found under Venice’s houses) and when a corpse found on the Isle of the Dead turns out to be that of the missing businessman he’s been looking for you’d expect that Zen’s luck has finally turned.
As it turns out, however, nothing could be further from the truth. While he may have put the pieces of the jigsaw together, he’s not able to use the solution to his own professional or financial advantage and he leaves Venice with his aspirations unfulfilled having made some influential enemies along the way.