Beria caught wind of it, and poisoned Stalin, allegedly, he told the rest of the Politburo, which was going to be purged, along with Beria himself, "I saved all of you."
Didn’t do Beria much good, huh?
The NKVD had gotten WAY too powerful by then, and Beria was a notorious sexual pervert, so the rest of the Politburo had him accused of spying and shot not long after Stalin died.