The storyline is that Heyman and Lesnar went to Vince McMahon and asked him to give Lesnar a match with Rey Mysterio to get payback for the steel chair beatdown that Rey put on Lesnar after Lesnar's quick win over Cain Velasquez at WWE Crown Jewel on Thursday. Heyman said Vince would not book Lesnar vs. Mysterio because blue brand Superstars are contractually exclusive to FOX these days, while red brand Superstars are contractually exclusive to the USA Network.
Heyman then announced that Lesnar has now quit SmackDown, and will be going to Monday's RAW from Long Island, NY to hunt Mysterio.
There's no word yet on where they are going with this new Lesnar storyline, but it could have something to do with "The Fiend" Bray Wyatt bringing the WWE Universal Title to SmackDown after defeating Seth Rollins for the title at Crown Jewel on Thursday. It was noted on Crown Jewel commentary that The Fiend will now keep the Universal Title on the blue brand.
Below are a few shots from tonight's opening angle at the KeyBank Center in Buffalo, NY: