Pen & Paper Bullshit

The accountant Nebinard "Nebby" Bichard is dead, done in by one of his fellow passengers on the Agatha Christie; thankfully, a private investigator, the esteemed Rampo Andromeda, is also on-board the ship and more then willing to solve this grisly murder. Why was poor, innocent Nebby murdered? Who could have a motive to murder someone they barely knew? Or was it all a prank gone wrong?