Ren does, indeed, see the large vine up ahead- and Akechi's right. Something about it is... off.

"... Is it shimmering?" He squints his eyes, carefully stepping a little closer. "Oh- it's-"

But he's cut off when something moves in the corner of his eyes, and as fast as he is to turn towards it, it's gone before he can catch... whatever it was. He's overcome with a horrible sense of foreboding, his ears twitching around to try and get more information.

"Did you see that?" he asks, turning to the other two. "It feels... like something's here."