Recon Bird

[The recon places 10 knives without seeing anything, the crew was only half paying attention when suddenly the recon bird, while placing its next 10 knives had entered a landscape of darkness. The recon bird stopped and chirped until the crew finally looked at the screen. The recon bird had found a giant chain reaching into the sky. Attached to something unknown. The chain itself was invisible but the glow told its location. The chain was weakened, a strong enough person could break it.]