1 - Captain America walks cautiously through an enormous room in an A.I.M. facility. The room is filled with computer consoles and all the things you would expect, but everything is completely covered by flora and fauna that is wrong, potentially not of this world. It's like a Lovecraftian jungle has invaded their HQ.
CAPTION (CAPTAIN AMERICA) (1): There should be A.I.M. scientists and soldiers everywhere.
CAPTION (CAPTAIN AMERICA) (2): Not... whatever this is.
2 - Inset panel. A small bug / reptilian creature is climbing up Cap's boot / leg.
LETTER NOTE: If you can, have Cap's second caption be near this part of the image.
3 - The creature is now on Cap's leg. It stabs him with a terrible stinger-thing. Background could be red to emphasize the pain.
4 - Cap is on the ground, one hand nursing his leg (which is already swelling up) and the other to his head. A shadow approaches from off-panel, its source unclear.
CAPTION (CAPTAIN AMERICA): Too late, I realize my mistake.
5 - On Cap's eyes. They stare out at the reader, red and without pupils (maybe bleeding?). A shape is reflected in his eyes, but it's vague and indistinct.
CAPTION (CAPTAIN AMERICA): So focused on seeing one problem...
6 - Back on Cap nursing his (even more swollen) leg. A huge, monstrous creature is right in front of him. It's made up of bodies of A.I.M agents, stacked and shambling one into another in a way that's impossible to tell where one ends and the next begins. It's not a pretty sight.
CAPTION (CAPTAIN AMERICA): I missed the one staring me in the face.