Judging by the premise of Monday's episode, it probably gets resolved pretty quick. They successfully communicate with Hank's ghost, and learn that Nero killed him. Only Hank probably knows him as Desmond and John or Charlie makes the connection.
#4.11 "Séance & Sensibility" LOVE IS ALL AROUND — When Mona (Ramona Young) discovers that her favorite author, Jane Austen (guest star Jenna Rosenow), might be at the epicenter of a magical alert, Mona, Sara (Caity Lotz), Charlie (Maisie Richardson-Sellers) and Zari (Tala Ashe) find themselves in 1809. With Nate (Nick Zano) still dealing with family issues, Constantine (Matt Ryan) and Rory (Dominic Purcell) perform a séance and receive a message from the other world that rocks Constantine to his core. Meanwhile, Ray (Brandon Routh) and Nora (Courtney Ford) are forced into close quarters. Alexandra La Roche directed the episode written by Grainne Godfree & Jackie Canino (#411).