Oliver Queen is calling up John Constantine for a favor.

The anti-hero of NBC’s short-lived Constantine will be a guest in the next episode of Arrow on the CW. A trailer aired after last night’s rather stellar episode, and for Constantine fans it tugs at the heart to see Matt Ryan in the trenchcoat and tie again.

In “Haunted,” Oliver will cash in a favor from the sarcastic exorcist to help save Sara, who hasn’t been herself since her Lazarus Pit resurrection.

Apparently Oliver and Constantine have some history together, which he of course never mentioned because he’s Oliver Queen, who keeps secrets inside secrets.

Could Constantine live again for a second season? Unlikely. However, Constantine production designer Dave Blass did tweet some hope, calling for fans to tune in because “they will take notice.”

Former Constantine writer and producer Daniel Cerone, who infamously showed NBC executives the hashtag #SaveConstantine trending during the failed second season pitch meeting, also tweeted similar sentiments.

It’ll be an uphill battle for both the Emerald Archer and the Hellblazer. Arrow ratings this season began strong but have steadily declined each week. Not that ratings should really matter anyway.

For a quick refresher on who John is and what happened to him, read our brief summary of Constantine.