Abigail Lincoln a.k.a. Numbuh 5 is an African American Kids Next Door Operative at Sector V. She became a KND operative three years before the show started as shown in Operation: M.A.U.R.I.C.E.. She was trained by her older sister, Cree (Numbuh 11), and joined her sister, Numbuhs 8a and 8b, and Numbuh 9 in Sector V. After Cree traitorously left the KND, Numbuh 5 became the leader of Sector V, until she allowed Numbuh 1 to take over after she found and hacked his grades for his KND Entrance Exam. She is the oldest member of Sector V.