Paul Manafort’s plea deal with special counsel Robert Mueller has fallen apart.

In a new court filing, Mueller accused Manafort of breaching their plea agreement from September — which required his cooperation in the investigation — by lying to them.

“After signing the plea agreement, Manafort committed federal crimes by lying to the Federal Bureau of Investigation and the Special Counsel’s Office on a variety of subject matters, which constitute breaches of the agreement,” Mueller’s team wrote.

The special counsel did not provide specifics on what Manafort allegedly lied about or what evidence they have about it. But the filing’s specific mention of crimes suggests that Manafort may be hit with yet more charges.

The defendant’s lawyers disputed the accusation, writing that Manafort “believes he has provided truthful information.” But both parties signaled that further cooperation would be fruitless, and said Manafort’s sentencing should be scheduled.

Manafort’s flip — which came after his conviction in one trial, and as he was preparing for a second trial — appeared to be a major turning point in the investigation. It seemed as if Mueller now had a cooperator who had close ties to both Trump and Russia (Manafort worked for Ukraine’s pro-Russian political faction for many years). But that cooperation, it appears, didn’t pan out.

One question is who this is worse news for: Mueller or Manafort? It’s possible that Mueller badly needed information or testimony from Manafort to make his larger case, and has now seen that possibility slip through his fingers. But it’s also possible that Mueller didn’t end up needing Manafort much after all, and got much of the information he wanted elsewhere.

Another question is: considering the serious legal consequences Manafort is likely to face for breaching his plea agreement, why would he (allegedly) lie to investigators? Could he have calculated that a presidential pardon would be his best chance of getting out of prison any time soon? Trump, after all, has refused to rule out pardoning Manafort and praised him even after his conviction, as he did in this August tweet:

Manafort’s long legal road

It was all the way back in October 2017 that Mueller first indicted Paul Manafort, for conspiracy, undeclared foreign lobbying, financial, and other crimes, alongside his longtime right hand man Rick Gates.

Though we know Mueller investigated Manafort’s involvement in Russian interference with the 2016 campaign, this indictment wasn’t about that. Instead, it was about years worth of lobbying work the pair did for Ukrainian politicians and government leaders prior to the campaign — and about what they did with their money afterward.

Speculation began instantly that Mueller was using these charges to try and pressure both Manafort and Gates to “flip” for the Russia investigation. But at first, neither did, and both pleaded not guilty.

Then in February, Mueller filed a new set of tax charges against the pair, again related to the Ukrainian money. (For jurisdictional reasons, he had to file them in Virginia, rather than adding them to the first charges in Washington, DC.) This spurred Gates — less wealthy and younger than Manafort — to strike a deal. He agreed to cooperate (against Manafort, and potentially more broadly) and pleaded guilty to a reduced set of charges.

Still, Manafort held out. But about four months later, in June, Mueller’s team added a new allegation against him — that he and a Russian associate, Konstantin Kilimnik, encouraged a likely witness in his upcoming trial to stick to a false story. The new charges led to Judge Amy Berman Jackson finding that Manafort had violated his conditions of release — and ordering him jailed (as he has been since).

The Virginia trial ended up being scheduled first, and began on July 31. Gates, and a plethora of other witnesses, took the stand against his former boss. And while Manafort’s team managed to get one holdout juror to vote against conviction on 10 counts — Mueller won a unanimous conviction on eight others.

With the conviction in the books and Manafort set to face a lengthy prison sentence, he was still facing at least one more trial (in Washington) and potentially a second (if Mueller retried the Virginia mistrial counts), Manafort finally came to the table — and agreed to cooperate. The deal was announced on September 7, and in the weeks after it, Manafort visited the special counsel’s offices many times for questioning.

But on November 9, Katherine Faulders, John Santucci, and Matthew Mosk of ABC News reported that “tensions” were “rising” between Mueller’s team and Manafort over his “apparent lack of cooperation with the investigation.” Then, on November 15, Mueller and Manafort’s team asked for a brief extension to file their next joint status report about his case — an extension until this Monday night.

And now, they’ve revealed why they did so — to announce that the whole “cooperation” thing wasn’t working out.