This is a pretty interesting card.

On the face of it, it has surprisingly good numbers - 2 rez cost for a 3-strength "end the run" gearcheck. That's solid! But then it has the weirdness of being both a code gate and a barrier, so it's a pretty forgiving gearcheck - they're likely to have something that can break it. But when they do, it's still not cheap. 3 strength for only 2 rez is solid, and very little breaks it for less than 2. (Begemot, Cleaver or a pumped Hyperbaric take 1, but Paperclip, Unity, Gordian Blade and Corroder are still 2, and almost everything else is worse.)

But the fun part, of course, is not the stats, but is that extra text. Trash a card, and oops, a runner card can't break ice now! Granted, it's only for the run, but disabling one of their cards has a VERY good chance of making the run impossible for the runner, if there is any ice behind this. Especially if they don't have a full rig yet, and are counting on something like Endurance or an AI to get them through.

As far as anti-boat-tech goes, it's not quite as good as NEXT Activation Command, which can block the boat for a whole turn, but this can work on actual icebreakers as well, as well as having the advantage of being a surprise. Since it will usually force the runner to run an extra time, it pairs nicely with most forms of click compression. (Manegarm Skunkworks, Anoetic Void, bioroids, etc.)

The downside, of course, is that even though this is a mid-run surprise, the runner is unlikely to get caught in too awkward a position by it, since most of the time you'll be rezzing it as they encounter it. So at worst, they will just bounce off the ETR sub or jack out, and run again next click, once their breakers are working again. In this way, it's sort of a Border Control-lite, except that they can get around it by having some extra breakers, and it sticks around providing some minor tax.

Much like Anemone, its ability to toss a card has nice synergy with all the fun archives tech Jinteki has been getting lately. It can ditch agendas for Regenesis. It can throw ice for Nanisivik Grid. It can just even just keep facedown cards in archives for Jinteki: Restoring Humanity.

Overall: Solid card. I'm definitely using it in my startup decks at the moment!

Also, if you're wondering, the name is a reference to a 500-year-old clam.

So, this card is part of one of the most disgusting combos in the game right now

Toss one Hafrún into a Ob together with some Stavka and have anything with a rez cost of 3 rezzed

When the runner approaches Stavka, you rez it, trash the 3-cost card and use Ob to bring Hafrún into the same server as Stavka is. At that moment you can trash one card from HQ to have one of their breakers stop working. If they only have one kind of breaker that can break it, then they're in very bad waters.

There's a few ways to survive this combo.

One of them is, of course, having more than one way of breaking a sentry. Maybe you have your killer, but you also have an AI.

Another way is using something like Flip Switch or Laser Pointer

The other big brain way of getting around this is using Simulchip to reinstall your malfunctioning breaker

But yeah, this combo exists in Startup at the time of this writing, and Simulchip/Flip Switch don't