The Sirens Sang Of Murder Hilary Tamar Series, Book 3.

Young barrsiter Michael Cantrip has skipped of to the Channel Islands to take on a tax-law case that's worth a fortune - if Cantrip's tax-planning cronies can locate the missing heir. But Cantrip has waded in way over his head. Strange things are happening on these mysterious, isolated isles. Something is going bump in the night - and bumping off members of the legal team, one by one. Soon Cantrip is telexing the gang at the home office for help....