Ambrose de Ripariis is a character who has few scenes in "Serch Bythol", but a huge impact, but he becomes a pivotal character in the three subsequent books.

Ambrose was the son of a French father and English mother. He grew up in Provence and moved to London in the early 1870s, upon inheriting a fine townhouse on Arlington Street. A few years after that, he met Nathaniel Ley, the beginning of a new old life for Ambrose.

Nathaniel provided the scientific knowledge Ambrose needed and the two forged a brilliant partnership. Despite the many curves in the road, Ambrose and Nathaniel remain outstanding partners and the best of friends.That comes to an end, however, when Nathaniel listens to the wrong voices.

A strong believer in multidimensional consciousness, Ambrose is the leader of the spirit family. He is accused of being detached and aloof by those who don't know him, but to those who do, he is the most loyal and loving friend for which anyone can ask.

Ambrose's life's work is helping his fellow human beings realize that they hold the power of the Universe within themselves. The words he placed above Beak's End when his name was Aloysius Ley were: Capax Infiniti, meaning "capable of the infinite". Ambrose is determined to tear apart the veil that separates the earthly and spiritual dimensions.

Ambrose is a Tantra adept who loves yoga, meditation, the fine arts, taking long walks, and studying the human condition. He is a superb pianist and dancer. Although Ambrose is a formidable Occultist, he only uses those powers on rare occasions.

His twin flame is Sophia, who was his wife in his former incarnation as Aloysius Ley, but Sophia is not reborn in this time. Their marriage was alternately tumultuous and edenic, but ultimately they had the same goal. His spirit twin is David, whom Ambrose feels the most like himself around.