UPDATE x 3: The following is from WWE.com:

Brock Lesnar and adviser Paul Heyman arrived unannounced at WWE headquarters in Stamford, Conn., Monday morning. WWE.com obtained a photo of the pair inside the lobby of the building.

Although the purpose of their visit is presently unclear, Heyman tweeted a series of messages alluding to a surprise that he and Lesnar would reveal on Raw, live on USA Network at 8/7 CT tonight.

UPDATE x 2: Paul Heyman posted the following updates via Twitter...

A personal note from my client @BrockLesnar to @TripleH ... WHY would you have a sledgehammer in your office? Someone could ...

UPDATE: Paul Heyman continues to tease something for RAW, posting the following…

My client @BrockLesnar is in a #BreakingNews sort of mood for @WWE #RAW. But we're not waiting til 2night!

ORIGINAL: Paul Heyman posted the following on Twitter…

#2EXTREME4WWE I like the adjective #EXTREME. So does my client. Hint hint for tomorrow's @WWE #RAW