(Please see all previous disclaimers, m preg)
Aquaformer carefully took off after making sure Bee and Mirage were okay with watching the little ones for a bit longer. Aquaformer knew her mate was not himself due to the sparking, and so she made sure to take off in her grounder mode. She knew she could've flown, but she didn't feel that was right, at least at this point. She wanted Optimus to have time to wear out whatever was going through his systems.
Meanwhile, many miles ahead of his mate, Optimus found himself in an area not only devoid of humans, but also devoid of much life in general save for a few random bushes and cactus. He hadn't been paying attention to where he was headed, and since he was lost in his own musings, he didn't realize he was in the middle of a desert. His spark, though, sensed danger and quietly pulsed to Aquaformer.
Back closer to the base, Aquaformer received the distress pulses, and realizing that getting to her mate was of utmost importance, she transformed to her aerial mode and followed the direction that Optimus' spark was giving to her, though he didn't know it. She feared for the safety of her mate and the developing little ones as the area that Optimus was in was no place for a sparked bot.
Soon, Aquaformer reached where her mate was, but in order to not scare or startle him, she transformed into her grounder mode about ten miles from where he was at and then drove to his location. Aquaformer didn't like this area because of how hot it could get. Thankfully, since the sun was setting, it wasn't as hot as it could have been. Aquaformer soon reached where her mate was. "Optimus?" She asked gently and lovingly in her deep feminine voice. She knew she had to be careful with him.
Optimus turned towards her, a bit surprised to see her, but he thought his processor was playing tricks on him. "You aren't here. You are just a mirage" Optimus responded, this sparking clouding the bots processor some what.
"No, my love. I am no mirage. Mirage is back home watching our little ones. I came to find you after you took off" Aquaformer quietly responded, wanting her sparked mate safe.
"No, you are just me imagining things out here" Optimus responded, showing he was low on energon. She knew it too, after that comment.
"Optimus, you are being delusional. Please, let me help you" Aquaformer begged. Optimus wanted to retort, but his weakened systems caused him to drop to one knee. Aquaformer carefully approached her distraught mate. She could see he was weak, but she knew how to help. Carefully, she slowly fed him cooled and sparked bot approved energon, hoping it would help reset her mate.
After five cubes of the appropriate type cooled energon, Optimus began to return to himself. He was stunned to find himself off the base and in the literal middle of nowhere. "What happened?" He asked, more like his regular self.
"You were low on energon and being sparked made you do something a little silly" Aquaformer responded, happy her mate was coming around.
"I did?" Optimus asked, curiously.
"Yes, you left the base and wound up in a desert" Aquaformer answered. Optimus could see his mate was right. He had left the base and ended up in the desert. But his mate had come to find him, and that he was truly grateful for. "Rest, Love. I have sent for Skyfire to come pick us both up, and then Ratchet will check us both out once we get back." Optimus just nodded, still too weak to do much. Little did Aquaformer or Optimus know that when they got back to the base, someone or something would be very impatient.