When Bret Taylor announced he was stepping down as co-CEO and co-chair at Salesforce in November, it was easy to be cynical about him saying he wanted to go build again. Well, guess what? He wanted to go build again — and today he and long time Google engineering veteran Clay Bavor announced they were teaming up on a new mystery project.

Bavor, who spent almost seven years as the VP of AR and VR at Google as part of an 18 year career with the company, was coy in a LinkedIn post about what is coming next, but he was clear he’s doing it with his pal Taylor.

He wrote that the two have known each other for years, since they broke in at Google together, and that he “always admired [Taylor’s] keen product sense and entrepreneurial spirit, his technical chops, and, above all, his character and integrity.”

Perhaps hinting at what comes next, Bavor wrote, “We share an obsession with recent advances in AI, and we’re excited to build a new company to apply AI to solve some of the most important problems in business.” Will it have an AR/VR flavor? It’s impossible to say right now, but the two have something cooking.

Whatever it is, he wasn’t saying specifically, but we might know more next month. “I’ll be setting out with Bret on this next adventure in March, and will have more to share once we get started. Until then, I’ll be focusing on transitioning my teams and projects, and wrapping things up properly at Google.”

Taylor spent four years at Google starting in March 2003 before undertaking an entrepreneurial journey, founding early social network FriendFeed in 2007, right after leaving Google. The company was purchased by Facebook in 2009 and Taylor had a stint as CTO at the company.

He would later found Quip, an enterprise document collaboration company, which was acquired by Salesforce in 2016 for $750 million. He climbed through the ranks to co-CEO, and now will be returning to his company building roots.

Whatever’s coming next, it should be interesting to find out.