"Their victims retain their physical strength during the day, so we can already rule out all the undead that would be harmed by exposure to the sun. Sadly, it doesn't narrow the research enough.
"Even if they belonged to an undead who is paralyzed during the day, we have no idea how Jiera's plague altered its metabolism. Maybe the tissues are still, but the organisms carrying them are not undead and allow the infection to spread even during the day." Kalla said.
"Then what are we doing here?" Friya asked. "Wouldn't it be better to get back at night, when all kinds of undead can freely move around?"
"We're doing research, child. If we find out that no undead matching the energy signature we are looking for is outside during the day, it means that they probably can't move.
"Also, this is the perfect time to look for Erlik. Draugr can't move as long as the sun is up, no matter if it's covered by clouds or leaves. If we find him, he can't escape."