High-powered attorneys from Wachtell, Lipton, Rosen & Katz representing Twitter are getting ready for a legal fight. The Musk Parties have filed a letter claiming that Elon Musk’s attempt to terminate a $44 billion acquisition of Twitter is invalid because “Mr. Musk and the other Musk Parties have knowingly, intentionally, willfully, and materially breached the Agreement,” after Musk finally filed paperwork last week.

William Savitt, a lawyer at Wachtell who has defended large corporations like Anthem and Sotheby’s in lawsuits against activist shareholders, is the attorney for Twitter.

Musk claims he wants to go because he believes Twitter has exaggerated the level of bot activity on the network, a problem he previously committed to address, and because Twitter won’t provide him with the information he needs to look into those allegations. Twitter claims to have provided him with all of the information he requested.