. Using the Probe Gun is simple enough. First activate the harpoons via marker following.
Then take the lift down into the organic beast. Once inside aim the Probe Gun and listen
for the beeping. When the beeping is really loud then fire a few shots.
. The first probe sent will reveal a low signal and a swarm of necromorphs. Kill
them all with the Probe Gun. You may want to play on an easier mode this can be
rough battle wise.
. The 2nd probe will be free of enemies. The final probe you shoot will release more
necromorphs and you must take them out to activate the lift to get back to safety.
After Norton's move on Issac, make your way towards the marker. Eventually you will
come to a cutscene where the beast shows it is actually alive.
. You must shoot the creatures yellow heart to have it take damage. There will
be small imp necromorphs popping out of sacks as well so take them out too.
. After wards the creature will open its mouth and reveal more yellow weak spots.
Destroy all of the yellow nodes and then be prepared to get eaten by the creature.
.Inside the stomach of the creature will be 3 tentacles. Shoot at the yellow
tips on each of the 3 tentacles. Once complete you will escape it's stomach
and end back up outside.
. Watch a great cut scene and complete the chapter !