Jarnsaxa did what she could for Magni and Matilda, but she didn’t have enough supplies or anti-venom for both of them. They were in danger of losing both of them. The next nearest source of medical supplies was Eggther’s camp.
Modi was all set to thunder into the camp and fight all 100-some giants to get the medicine, but the Scions were able to come up with another plan - Samuel and Abigail were to become giants in disguise and go into the camp. Sam was going to cause a distraction with Barry’s skateboard and Abigail would look for medicine during the chaos. They had to trust Loki with the magic to transform them, seeing as none of the rest of them knew magic powerful enough.
Under pressure, Loki agreed and turned Samuel and Abigail into giants. Samuel rode down the hill on the skateboard and headed towards the pen holding the hogzillas. He opened the gate, starting a stampede. Abigail was able to find the supplies they needed and the two of them snuck away in the chaos, undetected.
Jarnsaxa used the extra medicine to stabilize Matilda and Magni. Matilda would still need to get to a hospital, but she wasn’t going to die.
The Scions thanked Jarnsaxa and her sons and hurried with Loki back to the secret gate to Midgard. Samantha, in Astrid's body, carried Matilda along in her arms. She carried herself to safety. It was one of the oddest things she's done.