:Have you got any better ideas?:

Interrupted by a Mindtouch, Leareth lifts a hand. 

:Acknowledged: he tells Vanyel, curtly, and returns his attention to the conversation in front of him. :- Strange, message from Vanyel. They have both the other stones but are - handling a negotiation with past Natasha: 

:Got it.:

:Unfortunately,: says the Ancient One, answering Strange's earlier question, :I'm not sure there is a better way. Opposing someone who has all six Infinity Stones is—:

There's a burst of Infinity Stone magic from the top of Stark Tower, and Strange, Leareth, and the Ancient One all feel it. It's not the Stones that are supposed to be there—they felt those vanish a few minutes ago.

A purple giant wearing a golden gauntlet steps out of a cloud of black smoke streaked with blue and green lightning onto the helipad of Stark Tower.

"If it's all the same to you, I'll have that—"

And he freezes, because what he sees beyond the Avengers is so much worse than anything they or SHIELD or Odin can possibly do to him.

He remembers the Chitauri's words. He will make you long for something as sweet as pain.

Thanos raises his hand. The Mind Stone flares, and all the Avengers fall unconscious. He goes straight for Loki. Picks him up by the throat with his gauntleted hand.

"In the future I kill you for your treachery. Don't make me do it again."

Loki's voice is small and high-pitched.

"You—you won't need to, my lord," he manages to get out.

"Good. You're going to help me kill the Avengers. Not these ones" —he gestures to the unconscious forms around them—"the ones who are here from the future, trying to undo my work."

He drops Loki without waiting for a response, and the god of mischief falls unceremoniously to the ground.

The thing Leareth can actually sense, from here, is BLINDING MAGIC - no focus - it's six different sources of BLINDING MAGIC in slightly different flavours...

There is only one person who's known to have had all six stones at any point, and who has any reason at all to be here. 

Vanyel is the strongest Mindspeaker, and Leareth has enough rapport to find him in less than half a second; he includes Strange and the Ancient One in his rapid burst of Mindspeech, though he otherwise keeps it very carefully directionally shielded. 

:Thanos probably here from future - all six stones - you should LEAVE NOW -: 

Their party doesn't currently have all the Stones, and Leareth suspects they can't find Thanos head-to-head with the three they do have, and he doesn't know how Thanos followed them here or whether he can keep following them through time but there isn't going to be a lot of time - 

Vanyel is pretty sure Leareth and Nayoki discussed some kind of contingency for this but his mind is blank with surprise and shock. 

He relays Leareth's warning to everyone else in the warehouse, for lack of other ideas. :Brightstar can you -: 

Now that he has reason to look, Brightstar can in fact detect the six point-sources of magic, fifty miles or so away, and sends wordless confirmation. 

The contingency plan for if Thanos had time travel as well and could track them - or just made a correct inference about what they'd be doing and when they'd be visiting - was "get the hell out as fast as possible."

:Tony we're getting out: Nayoki barks to him, and reaches for the controls on her suit, to return to the Avengers' tower of the present day. 

Nothing happens. Thanos is blocking all time travel in or out within a hundred-mile radius of himself.

Tony throws the spare suit at Featherfire and taps frantically at the controls of his own suit.

"Fuck."

He tries a few more times, just to make sure.

"We should have thought of this—he has the Time Stone, of course he can block us from traveling—"

He radios Cap and Strange. "There's a situation. Thanos is here. Stopping us from leaving. Let's regroup at Cap's location—uh, wizards, you got that, right—?"

"Got it," says Strange via the radio, then Mindspeaks Leareth and the Ancient One. :We're regrouping at the spot where we came in,: he says, and opens the portal.

Leareth acknowledges this wordlessly and follows Strange.

It's less that he didn't think of this possibility, and more that it's not really clear what to do other than 'if you can't run, fight.' He went back and forth with Tony on the wisdom of a contingency plan that involved gathering all of them in one place versus dispersing; he's not entirely convinced the former is a good idea, but the latter isn't a great plan either. 

Nayoki is starting to get a bit winded from all the Gates. :Brightstar, can you -: 

Brightstar needs doors to use as Gate-thresholds, he can't do them on thin air (and until recently didn't know anyone could do that). The warehouse has a door though, and so do lots of the buildings where they landed, and he can do that from memory. Though the first try doesn't work because apparently the door he's anchoring on got blown up or collapsed in the interim. 

Within eight seconds or so there's a Gate up. 

Vanyel, as the most powerful and best at shielding himself, crosses first and scans the surroundings. 

There's nothing hostile nearby, except Thanos, who's still at Stark Tower.

"What happened?"

"We got Mind and Space to 2018. Then Thanos showed up—our Thanos, with all the Stones. He's blocking time travel out, somehow."

"We have our own Time Stone. Maybe we can get out with that."

He gestures wordlessly to the Ancient One.

She attempts to use her Time Stone to cancel the blocking effect in their immediate vicinity.

Green lightning arcs across the city from her Stone to the one in Thanos' gauntlet.