Angelica Mattheussens is on the medical team in the research hospital located in the basement of Corona Tower, serving as an administrative assistant.

Angelica has a scar on her forehead that her black bangs don't quite hide. Exceptionally punctual, Angelica expects the same of those around her.

Angelica's brother died in a car accident, and she suspects (without proof) that it was the occupational therapist Van Hermoso. She has seen his car, and the red paint on his bumper is too telling to be coincidence.

Angelica sleeps with a CPAP machine. Her sleeping disorder is stress related, and it gets worse when she spends time around Hermoso.

Angelica's problems with diabetes have so far hampered her desire to run the Bay City Marathon, but she can still dream, can't she? She volunteers at registration for the event every year.

We first meet Angelica Mattheussens in Book 3 of The Human-Hybrid Project, The Mirror Cracks.