Bob Haldeman, the president's chief of staff, had been on vacation and had little or no contact with the president from December 22 through January 2. On the 3rd, he was back in the Oval Office. His diary says it was a three hour meeting and he lists several things, but not Watergate...but the tape shows a great follow-up to yesterday's meeting between Chuck Colson and Nixon.
Haldeman: [...] There was more to his [Colson's] involvement in some of this stuff than I realized.
President Nixon: Really?
President Nixon: Which part?
President Nixon: Colson? Does he know?
Haldeman: I think he knows.
President Nixon: Does he know you know?
Haldeman: I don't think he knows I know.
President Nixon: What do you mean, through Hunt or what?
Haldeman: Yes, through Hunt and Liddy. And if Liddy decides to pull the cord, Colson could be in some real soup. Liddy can do it under oath and then Colson is in a position of having perjured himself. See, Colson and Mitchell have both perjured themselves under oath already...
President Nixon: You mean Colson was aware of the Watergate bugging? That's hard for me to believe.
Haldeman: Not only was he aware of it, but was pushing very hard for results, and very specifically that.
President Nixon: Who was he pushing?
Haldeman: Magruder and Liddy. And that's why we've got to be awful careful to take -- Liddy we're taking care of in one way. We've got to be very careful to take care of Magruder the right way, in the other way.
President Nixon: What about Magruder? What does he need, a job of some sort, or what?
Haldeman: Well, either a job or recognition so he can go out into something outside.[...]
President Nixon: Does Mitchell know that Colson was involved, and does Colson know that Mitchell was involved?
Haldeman: I think the answer is yes to both of those, although I'm sure Colson assumes that Mitchell was involved if he doesn't know that Colson was involved...
Haldeman: ...But Hunt also knows. See, if Hunt decided to talk he could really screw Colson. But apparently there's no real danger of that. There doesn't appear to be any great danger of Liddy flipping, and I think we're okay with Magruder. The other one that's a problem is Sloan, and he doesn't know enough, apparently, to matter, although he suspects a lot, and if they start him wandering along his suspicions he could make a lot of news, if not any illegal.
There's more, but that's enough. Remember once again: many of the tapes, this one included, remained secret until the mid-1990s. Congress only subpoenaed tapes of conversations they knew about, and they were mostly flying blind.
And note again: outside of the obvious fact that these two men are deeply engaged in a criminal conspiracy, there's also the fact that one of them is the Chief Executive of the United States, and is charged to "take Care that the Laws be faithfully executed."