Sam's whistle echoed through the whole area and even the Solar fragments heard it.
At that exact moment, Sam's beasts came out of their hiding and he also ran out towards them, but before they reached, his shadows who are hiding at the outskirts of the valley appeared in different positions at the edge and they stabbed a medium sized metallic pole that was hidden between the rubble.
The Solar fragments are distracted by the undead who looked like one of their own, that is the reason they didn't check the surroundings. Anyway the whole plan started with a giant underestimation of Sam from the Solar fragments.
They are so sure that Sam wouldn't be able to find the valley and the Space tunnel. They thought that he would panic from the start from the sudden attacks the news from the major powers, everything else. Even underestimation was a major understatement.