Karl's tracking. He's good at it. Probably the best tracker in the troop. A most useful asset, given how important it is to identify enemy's position from, ideally, out of view.

To his surprise he catches a scent that reminds him a lot of himself. For a good five minutes, he's confused. Has he been walking in circles, chasing his own tail? Well that would be embarrassing and he's got to hope nobody's noticed, he would never hear the end of it. Come to think of the matter, it's not the first time he feels like he's caught his own track in these woods...

But coming nose to nose with his sister?? in retrospect, he should've recognized it was her and not be so surprised. But that definitely sucks. All of a sudden, their entire battle plans sound obsolete and inappropriate.

“You!!”
“Inger?! WHAT are YOU doing here you witch?? I had forgotten you exist and liked it better this way...”
“You'd know it if you paid attention at all when intelligent people talk you dumb turkey! I was signed up for camp before you were...”
They pause, slowly, instinctively turning their backs on each other and glancing from left to right at the forest, each knowing that any attempt at alerting their friends, or any word slightly louder than a whisper, perhaps any abrupt move, could lead to the destruction of either, or both of them. Karl's also too taken aback, unsure about fighting his own sister. Definitely not because he thinks he could lose to her.
“Doesn't matter who was there first, Inger!”
“Only who's there last, agreed...”
“So you agree to get back on that bus now Inger? I'm serious...”
“Oh but I'm serious too bro, part of me doesn't want you to get hurt... so I'll issue this warning only once, start packing...”
“You can get lost, we'll crush you easily...”
“...or you can sink with your idiot ship, I don't care either way, just don't come crying for me to spare ya, cause I won't...”
As they growl and hiss, they slowly start walking away from the scene; when they cease to be able to hear each other's curses due to ambient noises drowning them, they know to stop and take off to their respective safety, hearts beating with fear and anger from the encounter.

Do they hate each other that much, more than they use to under normal circumstances? Or are they baring teeth to try and protect each other in a way?