Sarah kept feeling more energized every day, and she felt hornier as well. Being around Mike was getting harder, as she exuded lust, and she was getting more dominant. The sexual tension was too much for Mike to handle, as they had promised not to have sex before marriage. In addition, Mike noticed how strong Sarah became, and how her body had filled incredibly quick with sexy lean mass in all the right places.
He kept asking her if she has done anything special, but Sarah has no idea what's going on with her. He also noticed just how strong and energic Lucy became, so whatever was happening to Sarah affected the dog as well. Mike pointed out that fact, so he asked Sarah if she has taken Lucy to any new places, or exposed her to anything unusual. Then, Sarah remembered she had visited the lake a couple times lately, and that's when she started to feel that way. Mike asked her not to go to the lake for some time, and she promised she wouldn't get close to it for a while.
Mike however had to learn what was going on at the lake, so he immediately went to check it out. Nothing seemed to be out of the ordinary, and the water looked particularly clean. Not many people went to that lake, as it was located in an unknown spot, so he just took off all his clothes and decided to go for a swim and check for anything that could explain Sarah's recent changes. It was slightly late, so the water felt cold, but he didn't mind it. He took a deep breath, and using the moonlight as his only guide, he dove to the depths of the lake. He went in and out of the water several times, until he finally managed to find a barrel at the bottom of the lake. He tried to move it, but it was too heavy for him. He noticed how a side of it leaked some greenish bubbles.
"Is anybody there?" an unknown male voice sounded. Mike was shocked, so he gasped and swallowed water. He had to immediately resurface, and he coughed some of the water as he emerges from the lake. "What are you doing there? Are you OK?" a man inquired, standing by Mike's clothes.
"Yeah! You scared me!" Mike replied. It was just an old man taking a walk by the lake.
"How is the water, son?" the man asked, smiling.
"It feels great," Mike said. The man went on his way, and Mike waited for him to disappear before approaching his clothes. He didn't want to be seen naked.
After that incident, Mike got back home, but he couldn't stop thinking about that mysterious barrel at the bottom of the lake, and if it was what caused Sarah's changes. After a few hours of feeling oddly energic and anxious, he finally fell asleep.
When dawn arrived, he woke up with a raging morning wood and an incredible amount of energy. He immediately saw how his bulge was tenting quite highly on his bed sheets. "Whoa! Someone woke up feeling good," Mike claimed, and he went to the bathroom. He usually slept naked, except when he slept with Sarah, so as soon as he entered his bathroom, the full length mirror revealed a shocking change. Previously, he was in good shape because he ran with Sarah, but now he was ripped and full of hard muscle mass. His manly tool had changed as well, as it grew from a modest 4 inch dick to a more serious 7 incher. He weighed himself and he noticed how he gained 35 pounds of lean mass overnight.
"Whoa! How is this possible?" he said, as he kept flexing his new muscles. His stomach was flat before, but now he sported an 8-pack that would make most men jealous. He took a shower and jerked off furiously, unloading an incredible amount of cum. "Whatever is in that barrel... That must be the reason..." he said with an evil grin, imagingin all the possiblities, as his mind was starting to get clouded by lust, an even greater lust than the one afflicting Sarah.