Agent Angel

Angels Unlimited is the title of a series of novels written for young adults by Annie Dalton. The books are based around Melanie Beeby, who is killed in a traffic accident on the day after her thirteenth birthday. She then finds herself transported to Heaven. The Heaven of this universe is a lively and vibrant city, populated both by dead humans-turned-angels and Heaven-born beings known as pure angels. This city is also where the headquarters of the Agency are situated. The Agency is an elite group whose job is to counter the Opposition, informally known as the PO Ds or Powers Of Darkness - the polar opposite of the Agency.

Upon arrival, Mel discovers that she is to be a trainee at the Angel Academy.

Each book features time travel of some kind, where Mel is tasked by the Agency to unravel various celestial problems involving humans and the Opposition. As of July 1, 2008 there are twelve novels and three omnibus books. On May 5, 2005, the Angels Unlimited series was renamed the Agent Angel series, and new covers were released for each book.

Tropes associated with Agent Angel:

 * Blond Guys Are Evil: Brice has a bleach-blond mullet.
 * Chained to a Railway: Miss Bloom is tied to the train tracks whilst filming a movie--with her brother crouching just out of shot with knife, in case a train really does come.
 * Dead All Along: Melanie is narrating from 'Heaven' about her adventures
 * Kidnapped by an Ally: Mel is a victim of this in. It has been speculated this was mainly for the benefit of older readers, considering who kidnapped her.
 * Time Travel: In the afterlife, Melanie travels to different eras in each book
 * Our Angels Are Different: Very much so.