Jolene Granger was a murder victim who purchased drugs from Chad Rodrick and gave them to Hal Lockwood to help him. Jolene was found in her apartment tied up on the floor, and it looked like she was strangled to death. Her phone was taken by Lockwood as it had his phone number on it from a call she made it to him shortly before her death. Castle and Beckett realize this and access her cell phone account, find Lockwood's number and arrest him, saving Ryan and Esposito.