And at Camp David, John Dean is writing, or not writing, the Dean Report. Which, if completed, was to be used to exonerate and protect the president -- but, as Dean realizes, only by landing the responsibility for the cover-up squarely on John Dean.
Dean's suggestion, which he's made before but pushes again on the phone this weekend to Haldeman, is for Dean to go to the soon-to-be-revived grand jury, get immunity, and then tell the truth about Watergate. At least from Dean on down. Obviously, an appealing strategy for Dean! But not so much for the others (who might not trust that Dean's new story would survive the grand jury, and that once he has immunity he might just rat out the rest of them).
The idea just doesn't really make sense for the president or the rest of them (and certainly not for Magruder or Mitchell, who Dean would presumably implicate), although Dean keeps returning to it. And at any rate, it wouldn't have worked; Dean couldn't have received complete immunity regardless, and surely not without inflicting more damage than any of them were prepared to accept.
But that leaves them -- and Dean in particular -- with no good options.