Ambrose Chase is the son of a survivor of Science City Zero, a genetic experimentation facility. Because of his relationship to that facility, Ambrose (and his abilities) came to the attention of the Planetary organization very early on. He knew Elijah Snow virtually his entire life and the two became good friends. Ambrose joined the Planetary field team alongside Elijah and Jakita Wagner. Ambrose was present during the mission that resulted in the rescue and recruitment of The Little Drummer Boy. In 1994, Elijah revealed to Ambrose that he was Planetary's mysterious Fourth Man and warned him of a coming change, which turned out to be Elijah's departure from Planetary, due to The Four's mental blocks. Ambrose took up leadership of the field team in Elijah's absence.
In 1997, Ambrose Chase led the field team on a raid of a heavily fortified research facility sponsored by The Four in England. The aim of the facility was to retrieve a being from a fictional reality dubbed "Planet Fiction". Ambrose, Jakita and The Drummer made their way through the facility and, while The Drummer retrieved information and Jakita occupied the ground troops, Ambrose ran up a wall to the main control room in an attempt to stop the facility's operations. When he reached the window of the control room, however, the facility's lead scientist pulled a gun and shot him six times. As Ambrose's field failed and he fell back to the facility's ground floor, the scientist declared that they were in a science fiction movie and that "the black guy always dies in science fiction movies." The Drummer and Jakita comforted Ambrose until he apparently vanished into his field; Jakita then killed Ambrose's murderer for revenge.
There is a strong implication that, despite his wounds, Ambrose somehow survived. The Drummer has hypothesized that Elijah's function as a century baby is to save things as Elijah sets his sights on Ambrose Chase's salvation, among other things.
Ambrose is survived by his widow, Larissa and his daughter, Angela. The Planetary foundation had been paying Larissa compensation for Ambrose's service since his death, but after Elijah regained his memories, he and Jakita visited Larissa to inform her that Elijah would personally see to her finances from then on, out of respect for Ambrose.
Following The Four's defeat, Planetary have to pop a distortion bubble that Ambrose created around himself just after he was shot. This bubble had him frozen in time and hidden from reality for a few years until the Planetary team could create a time machine which would bring him back into the present reality. Despite a power surge problem Ambrose reappears and is still heavily wounded from his gunshot wound. With a time machine now in existence teams comprising of Elijah Snow, Jakita and the Drummer from the future blink into existence to witness the event. They stated that they are unaware of the outcome of whether Ambrose will live and uncertainty principles are in place. A prepared team of medics begin work on him immediately and it appears that he is now dead. At that point a future version of Ambrose appears with each of the other future Planetary teams and says he thought it would be funnier this way and the medics take the Ambrose from that present off for surgery as it appears he is stable enough after all. He thanks Elijah for saving his life.
- Selective Physics Distortion Field: This field enabled Ambrose to bend the laws of physics within limits. Ambrose could use the field on himself, project it over a large area of unspecified dimensions, or concentrate it onto a smaller area or object, such as another person.
- Marksmanship: Ambrose is an expert marksman and used a pair of semi-automatic pistols, kept under his coat in holsters on the back of his belt, on field missions.
- The loss of, and attempt to save, Chase has been described as a surrogate for Warren Ellis' loss of his father during the production of Planetary.
- 7 Appearances of Ambrose Chase (Wildstorm Universe)
- 1 Images featuring Ambrose Chase (Wildstorm Universe)
- Quotations by or about Ambrose Chase (Wildstorm Universe)
- Character Gallery: Ambrose Chase (Wildstorm Universe)