Isabela Keyes a key character in Dead Rising, Dead Rising 2: Case West and Dead Rising 3. She is also mentioned but does not make an appearance in Dead Rising 2.

Isabela is the younger sister of Carlito Keyes, the mastermind behind the Willamette Incident during the events of Dead Rising. She helps her brother infect the population of Willamette as an act of vengeance for the destruction of Santa Cabeza. After seeing what her actions have caused, she has a change of heart and helps Frank West stop her brother from infecting the entire country.

She also creates the first zombie inhibitor using Queens in order to slow the zombification process. This idea was used by Phenotrans in order to market Zombrex. She is working for Phenotrans, trying to develop a cure for the zombie pandemic during the events of Dead Rising 2: Case West when she acts as Frank's source.

Her whereabouts remain unknown after the explosion at the Phenotrans Facility at the end of Case West until she resurfaces ten years later in Dead Rising 3. She is searching for Nick to use his blood to create a permanent cure for zombification in hopes that it will clear her family's name.

Deep pitch and caring.