In the next episode of "Gotham," detective James Gordon (Ben McKenzie) and Bruce Wayne (David Mazouz) seek answers about the mysterious knife that Wayne bought from an auction.

In the trailer for the new installment titled "The Demon's Head," Wayne goes to an artifacts historian and asks, "I want to know exactly what it is I bought." The elderly curator inspects the curved knife with the diamond-encrusted handle. In another scene, Gordon confronts Wayne, "You want to play detective? Who's Ra's al Ghul?" Wayne just looks at him surprised.

Apparently, both of them are looking for answers in the same direction. Gordon then asks the young Wayne why people are dying because of the knife. He eventually gets into a fight in a later scene with Ra's al Ghul (Alexander Siddig). They fight in an old library and exchange blows and kicks.

In the last scene, Barbara Kean asks the mysterious Ra's al Ghul (Alexander Siddig), "What's so special about this knife?" Ghul replies that the weapon is headed for a destiny that is going to be culminated after 2000 years. It remains to be seen who Ghul is and what his plans are with the deadly knife.

In the previous episode, Wayne bought the ancient knife from an auction organized by Penguin a.k.a. Oswald Cobblepot (Robin Lord Taylor). He found out that Penguin acquired it illegally from another country and that Ghul wanted it badly. Therefore, Wayne decided to buy it and even paid two million dollars to get the knife.

Kean was at the auction as well and tried to acquire it for Ghul but was outbid by Wayne, who was pretending to be a loud brat to hide his true motives and intentions.

"Gotham" season 4 episode 4 will air on Thursday, Oct. 12 at 8 p.m. EDT on Fox.