The indictments and plea agreement unsealed yesterday by Special Counsel Bob Mueller made news for their disclosures, but the documents were equally rich with intimations that Mueller chose not to spell out. I make no claim to know his thinking, but I have some acquaintance with his methods and style. I want to make a few observations—some of them admittedly speculative—that are not obvious in early coverage of the news.

Mueller’s choices in this first public release were tailored less to display his progress than to pave the way for more. The Office of Special Counsel is playing a long game. It has no alternative in an investigation of this breadth and national import. Mueller is demonstrating that long does not mean slow or uneventful.

The messages embedded in yesterday’s legal prose, some opaque and others quite precise, were calculated to shake loose information. Investigators sneak up on their targets as long as they can catch them unawares. When they exhaust those opportunities, or choose to supplement them, prosecutors and FBI agents turn to other tools.

We lack the context to read all the clues, but I am pretty sure Mueller crafted parts of his message for specific eyes. The intended recipients will know who they are and pick up on nuances that we cannot discern. They will also notice gaps and ambiguities that leave them off balance. I won’t try to guess at those mysteries, but Mueller conveyed other messages that anyone connected to this case can read.

What stands out for me is Mueller’s strategic use of implicit threat.

What stands out for me is Mueller’s strategic use of implicit threat. Some of the jeopardy facing Paul Manafort and Richard Gates is spelled out plainly in the twelve felony charges of their indictment. Other risks are merely intimated in passing. By analogy, other targets and witnesses in this probe will not find it hard to imagine themselves in Mueller’s sights.

Two examples. Count 35 against Manafort makes no allegation against his son-in-law, but it hints at potential exposure to a charge of bank fraud. The indictment quotes Manafort’s end of an email exchange, in which he reminds his son-in-law to pretend that he lives in one of Manafort’s condos in order to secure a better loan rate on the property. Mueller does not say how the son-in-law responded or what he told to the bank inspector. Manafort knows whether the next steps in that transaction might implicate his family. Counts 38 and 41 include the ominous phrase, “together with others.” The others, some of whom Mueller may not even know about, will be measuring themselves as potential defendants and worrying that they will not learn Mueller’s intentions until it’s too late to make a deal.

The guilty plea of George Papadopolous is even more interesting. Prosecutors control the statement of facts in almost any plea. This one sends three messages, at least.

First, the special counsel’s office knows a lot about the campaign’s interactions with Russia. It has emails and it has an eager “cooperator.” The Papadopoulos plea reads in that respect as a warning to other witnesses against perjury.

Second, Mueller is conspicuously not describing the boundaries of his knowledge. He isn’t saying, either, how he knows. He mentions fragments of records that, if he obtained them in full, might compromise other and more senior figures in the campaign. On several occasions, in his sworn plea statement, Papadopoulos describes reports he sent to top campaign officials about Russian overtures. He says very little about the replies, and his statement most likely left out other meetings and communications that his interlocutors will recall. Uncertainty inspires dread, and Mueller deployed it to flush out witnesses and evidence that he may not even know exists.

Uncertainty inspires dread, and Mueller deployed it to flush out witnesses and evidence that he may not even know exists.

Third, early cooperation with the probe, especially from people below the top, will save them from the worst of their jeopardy. Based only on the facts that Papadopoulos affirmed under oath, Mueller could have charged him more aggressively.

This is classic use of leverage on Mueller’s part. Prosecutors have enormous discretion at this stage of an investigation. I used to cover the courthouse in Washington, D.C., and there were times I thought they used that discretion unjustly. But like it or not, you can boil down Mueller’s message to four short sentences:

He may already know what you’re hiding. He’ll scorch you and yours if you lie. Spill it and he’ll go easier. And don’t wait too long.