TV Article 'Castle' taps 'The Neighbors' alum as new series regular By Natalie Abrams Natalie Abrams Senior Writer EW's editorial guidelines Published on July 7, 2015 06:23PM EDT Photo: Richard Cartwright/ABC; David Livingston/Getty Images Toks Olagundoye has joined the cast of Castle as a new series regular, EW has learned. The Neighbors alum will play Hayley Vargas, a quick-witted, free-spirited former Scotland Yard police officer who works as a security specialist and is not afraid to cross lines to get things done. Olagundoye’s casting comes amid big changes over at Castle in its eighth season. In addition to Penny Johnson Jerald not returning, the show has added two new co-showrunners, Terence Paul Winter and Alexi Hawley. Castle returns Monday, Sept. 21 at 10 p.m. ET on ABC.