After a series of twists and turns on Friday, Uber’s legal struggle with Alphabet‘s Waymo just got much simpler — in a way.

Indeed, in a new legal filing, Uber argues the fight basically comes down to one star engineer and his $120 million bonus from Alphabet — which he allegedly really, really wanted.

The battle centers around Anthony Levandowski, who was deeply involved in Google’s self-driving car initiative before leaving to found a start-up, Otto, which Uber later acquired. Waymo’s lawyers have asserted that Levandowski stole 14,000-plus documents from Alphabet, and that Levandowski was already negotiating with Uber before he left Alphabet.

The question now before the courts is whether Levandowski’s documents, including Alphabet trade secrets, were used to develop Uber’s self-driving cars.

Levandowski was paid generously at Google, by a division that is now Alphabet’s Waymo. He collected $120 million from Google, despite involvement with at least one start-up that would ultimately compete with his employer, Waymo said.

But Uber said on Friday that Levandowski downloaded the documents to compile extensive evidence that he deserved a bonus, and just happened to hang on to them. Indeed, Uber said that Levandowski admitted as much to former Uber CEO Travis Kalanick and that the corresponding files were supposed to be destroyed during Uber’s acquisition of Otto.

“Levandowski downloaded the files in connection with ensuring payment of his $120 million Google bonus,” an Uber spokesperson said. “Even if Levandowski did what Waymo says he did, he did it as a Google employee, for reasons unrelated to his future employment at Uber.”

Uber has proposed a detailed line of questioning, with more than 10 questions directly related to how concerned Levandowski was about his bonus.

To be sure, these allegations are just one side of the story — Waymo did not immediately respond to a request for comment. Levandowski has invoked his Fifth Amendment rights throughout the process, and his lawyers were not immediately available for comment. Uber said it might not even call Levandowski as a witness during a trial.

But Uber could depose Google founder Larry Page. Google parent Alphabet has already walked back most of its accusations against Uber, with only one piece of technology still under dispute.

“We found after fighting for discovery a device created by Anthony Levandowski at Uber that infringed Waymo patents,” Waymo said. “Uber has assured the court in statements made under penalty of perjury that it no longer uses and will not use that device, so we have narrowed the issues for trial by dismissing the patent claims as to that device, with the right to re-file suit if needed.

“We continue to pursue a patent claim against Uber’s current generation device and our trade secret claims, which are not at all affected by this stipulated dismissal. We look forward to trial.”