There isn't, technically, a supervillain "beat". Not at the Planet, which is a reputable newspaper that doesn't want its reporters' lives endangered. Not at the Star, which is a slightly less reputable newspaper that would still rather not hemorrhage reporters. You have to go pretty low before they'd be willing to cover active supervillainy, put themselves at risk in the name of pushing copy, and if you're already a tabloid you're not going to be doing a ton of investigative reporting anyway. Who's going to investigate when some asshole in spandex starts vaporizing people?
Well. Tintin, obviously.
He's in Metropolis when it happens. MBC footage of a battle between Superman and Batman. Batman goes down hard. Tintin's out of the sports bar before it's over, letting his interviewee assume he's going to ground in some bunker somewhere. He considers subspacing to the Watchtower. Discards the idea out of hand. Where is he going to find someone pointing their brain at a mostly secret spy satellite? He'll have to go with plan B.
The Hall of Justice, which, let's be honest, is basically a tourist trap, is being evacuated. It's always struck Tintin as ironic how easy it is to get into a place that's trying to get everybody out. The open second-floor window helps. He slips into the specific men's room which has been frequented by a suspicious number of billionaires on suspiciously timed visits to Metropolis. (There's also a ladies' room with the same distinction, which makes him slightly more confident that it isn't just a very nice glory hole.)
Zeta tubes can be hidden behind any number of things. He's banking on a holographic wall. How many people touch the far wall of an executive washroom? How many people touch the walls of any washroom? A quick sonar pulse from his "wristwatch" confirms it, and he steps on through.
It's not access-listed. Well, obviously. They don't want to have to key in every Bill and Melinda who come through, that'd just be silly.
As he beams up, he hopes he can come up with an actual plan at some point.