Twitter lawyered up. The company reportedly hired Wachtell, Lipton, Rosen & Katz, a firm notable enough to have its own Wikipedia page, and a founding partner, Martin Lipton, credited with inventing the shareholder rights plan or “poison pill” defense that Twitter initially used to put the brakes on Musk’s attempted buyout.

On Friday, Elon Musk filed a document to attempt to cancel his $44 billion takeover of Twitter. In response, Twitter chairman Bret Taylor tweeted the company would pursue legal action to close the deal as agreed upon. Wachtell Lipton’s hiring, as reported by Bloomberg, suggests Twitter is serious about arguing its case in the Delaware Court of Chancery.

During an appearance at the Sun Valley Conference this weekend Musk declined to take questions, but he has responded on Twitter.

Twitter hired two key lawyers for its team. One is William Savitt, who has represented companies like Anthem and Sotheby’s in the Delaware court against activist investors. The other is Leo Strine, a former Chancellor of the Delaware Chancery Court with 20 years of experience as a judge in the state’s courts, ending with a stint as the Chief Justice of its state Supreme Court before he joined the firm in 2020.

Musk is said to have hired Quinn Emanuel Urquhart & Sullivan, which also has received the Wikipedia treatment, and may be more familiar to Verge readers. It handled Samsung’s defense against Apple’s patent lawsuit claiming the Galaxy devices were merely a copycat of the iPhone, and has defended Musk previously, in his “pedo guy” defamation case, as well as the aftermath of his “funding secured” tweet about taking Tesla private in cases against the SEC and an ongoing shareholder lawsuit.

Update July 11th, 12:19AM ET: Added Elon Musk tweet.