Vanish from Sight

Event. Cost: 0.

Play only if you control 2 or fewer heroes.

Action: Until the end of the phase, if your threat is higher than 20, treat your threat as if it is 20.

"I see now little hope, if we do not soon vanish from sight for a while, and cover our trail."
Gandalf, The Fellowship of the Ring
Nikolas Hagialas

Flight of the Stormcaller #11. Neutral.

Vanish from Sight
Reviews

I want to like all cards. I want to find a fringe case for every one. This card is very difficult to do just that, but let me try:

Let's start with the reasonable scenarios of controlling 2 or fewer heroes:

1) Running a contract that demands it, such as The Grey Wanderer or At the End of All Things.

2) You deliberately sacrifice your hero, such as Boromir or Caldara

3) You are lending your hero to another player with Desperate Alliance

4) You lose control of a hero in a rescue mission style scenario (akin to Escape from Dol Guldur, but in that case, I believe it's been ruled that you still "control" your captured hero)

Now how could this card help in the above scenarios?

If you are utilizing your threat but include secrecy cards that become more expensive when your threat goes above 20, then this card is certainly a good one to play in the planning phase.

OR

Played during the encounter phase in order to dodge an enemy

OR

To trigger special "enemy's engagement cost higher than your threat" text such as Dagger of Westernesse, Sam Gamgee, and Boromir, most often during either the encounter or combat phases.

There's also a cool combo using A Elbereth! Gilthoniel! that can significantly lower your threat -- for example if your threat is 40, and you are being attacked by an enemy whose engagement cost is 21, if you play Vanish from Sight, not only do you kick this enemy to the bottom of the encounter deck (for free, since you are in secrecy) but you also drop your threat to 21.

Alright short of that... bicycle spokes.

Jtothemac 484
it can also help in rare occasions where you cannot reduce your thread like mt. doom but it is very cornercasy, yes. — doomguard 2220
It has been clarified by Caleb that you can't use Vanish from Sight+A Elbereth! Gilthoniel! to reduce your threat in Dire quests like Mt. Doom — Emmental 488
True, but Vanish from Sight can still help with Fortitude Tests. — Alonewolf87 2482
and avoid engaging — doomguard 2220
Tell me how the combination Vanish from Sight + An Elbereth works! Gilthoniel!? Does it reduce the threat or how? — Sayron13 1
Let's say you are at 35 threat and you engage an enemy with 25 engagement cost. If you first play Vanish from Sight (so your threat is considered 20) and then A! Elbereth after the enemy attacks you (note that you will also get the secrecy discount) your threat will be set at 25 by A! Elbereth effect, effectively reducing your threat by 10 — Alonewolf87 2482