The engine explosion was a huge setback for their plans to set off during the week and would probably mean they'd need to get accustomed to the Lousiana wetlands as even with the right parts, fixing the engine was a difficult task. The problem was they didn't have enough materials to rebuild the engine and someone would need to go to the nearest city and buy them.
Medusa was beyond upset, it was the first time they saw her curse like that and they were so intimidated by her no one dared to oppose when she ordered Uriel and Nika to go find the parts. Even in her enraged mood, Medusa kept at least a hint of her logical thinking and asked them because Uriel could ride the jaguar while Nika remained on his shadow. The fact that she didn't want Luna to spend any more time with Uriel was completely unrelated to her decision. Well, maybe not entirely as Medusa couldn't hide a smug when Luna complained because she wouldn't be able to go with them.