This would be interesting under any circumstances but it’s fascinating in the context of the beef on Fox News’s airwaves this week between Shep Smith and Andrew Napolitano on the one hand and Tucker Carlson and Joe diGenova on the other.

In case you slept through all that, Napolitano went on Shep’s show and accused Trump of having committed a crime by soliciting a “thing of value” to his 2020 campaign from a foreign national when he asked Ukraine’s president to investigate Joe Biden. That night diGenova appeared on Tucker’s show and called Napolitano a “fool” for believing that. The next day Shep used a minute of his own show to scold diGenova and Tucker, calling it “repugnant” that one Fox guest would denigrate the professional opinion of a Fox contributor. Tucker doubled down by bringing diGenova back on his show that night and all but calling Shep a liberal hack. Reportedly Fox execs intervened at that point, warning Shep not to hit back again. But the damage was done: The simmering feud between Fox’s Trump-skeptic news division and its Trump-admiring opinion division was now boiling after the prospect of impeachment had turned up the heat.

It looked like things had begun to cool down after Fox management stepped in — until this morning, when Chris Wallace pulled the pin on this grenade and lobbed it.

Breaking news on FOX News Sunday: Chris reports Rudy Giuliani did not act alone in trying to get dirt from Ukraine on Joe Biden… and much more.

Then– Kevin Corke discusses further information on the Trump whistleblower complaint and the Democrat's push for impeachment. pic.twitter.com/OpGRMArMHz

— FoxNewsSunday (@FoxNewsSunday) September 29, 2019

According to Wallace, diGenova is working with Giuliani on the Biden business with Ukraine. The guy whom Tucker invited on as some sort of dispassionate legal analyst to counter Napolitano turns out to be a secret participant in the matter that’s being analyzed, Trump’s interactions with Zelensky and his government. I didn’t see the first Tucker segment with diGenova but you can watch the second here. He’s introduced merely as a former U.S. Attorney, and Carlson prefaces their conversation by noting that legal opinion is split on the point about a “thing of value” that Napolitano had made. In other words, diGenova was presented to the audience as nothing more or less than a seasoned lawyer whose acumen led him to a different opinion than Judge Nap’s. Tucker even laughed at one point at Shep’s claim that diGenova is a “partisan.”

Now here comes Wallace to imply that the entire segment was basically a fraud, with diGenova concealing a glaring conflict of interest.

The news division just pantsed the opinion division, in other words. And they did it in a way that cuts to the heart of the criticism of Fox primetime over the past two and a half years, that it’s so deep in the tank for Trump that it’s hard to tell if its employees are working for the network or for the president. In this case, unbeknownst to the audience, one key guest was quite literally working for the president, Wallace claims.

Did Tucker know and conceal the information? Presumably he was in the dark, but he’s a buddy of Trump’s and has been known to talk foreign policy with him by phone. Did Trump ever idly mention to him that Rudy *and Joe diGenova* are working on the Ukraine thing? Also: Did Fox executives know of diGenova’s role? If so, why did they conceal the conflict of interest? If not, will there be any sanction against diGenova for not disclosing his involvement in the Ukraine stuff before appearing on a segment to comment on it?

Relatedly, who greenlit this on-air revelation by Wallace? It’s to Fox’s credit that they allowed it to be reported knowing the questions it would raise about diGenova’s segments this week and his role on the network going forward, but I’m surprised that they allowed it to be done in such a showy way. They could have relegated it to a story on the Fox News website and then quietly warned Tucker not to have him back on, or at least to be forthright about disclosing his role in the Ukraine matter next time.

One more: Will Shep be allowed to mention this on air tomorrow?

In lieu of an exit question, here’s the latest punch-up on Fox News between news and opinion. This clip earned a retweet from the president himself this morning.

“My question is: why is Joe Biden above the law?” –@marklevinshow pic.twitter.com/uJpvcrhY3a

— GOP (@GOP) September 29, 2019

Update: A Fox spokesperson emailed to say that management denies having had any direct conversation with Shep Smith.