Accounts Payable is the pre-quel to Haven of Danger: A Nathan Vallor Investigation. This is when Nathan first meets his future fiancée Jillian Hudson when he investigates Jillian's husband's death at the bequest of Nathan's sister Anne to keep an eye on her. It takes place in Richmond, Virginia, Nathan's hometown. He manages to protect the innocent and bring the bad guys down and narrowly avoids getting his own ticket punched in an accounting coverup that involves credits of money and debits of murder.