The Doctor and Shirley were in a garage, the Doctor in a hazmat suit building a small nuclear battery for what seemed to be a firearm. After finishing the lead casing, she decontaminated herself, put the battery down for a moment, and took off the suit. As the Doctor put her skirt over her underclothes, Shirley moved closer towards the battery. "So you put this into the cannon and it will provide enough energy to pierce the skin of the Time Vortex?" she asked.

"I do." the Doctor replied, "Humans keep forgetting how powerful Pluto-Thorium energy is." The Doctor put on her sweater. "Now we just need to see if the cannon can actually tear through the Time Vortex..." The Doctor got her shawl on and satchel over her shoulder. "...or at least a simulation of it."

While the Doctor and Shirley were testing a cannon on a manufactured high wind current, Susan got to Jo's home. "I've never thought that the Doctor would visit my home, especially a version of them from another universe." Jo said as the both of them took off their coats.

"I'm surprised no version of me has." Susan replied, "You're nice, even if it looks like people see you as dim." Susan noticed a photograph with Jo and a man in it. "Who's that man with the bob?"

Jo looked around and saw the photograph Susan was talking about. "Clifford. My husband. He died a hero..." Jo let out a single tear. "Truth be told, I wish I died with him sometimes."

"Oh, Jo." Susan hugged Jo tightly. "I'm sorry. I didn't know."

"Don't be sorry. You're not from this world and you don't know me. What matters more is that you get home. Until then, want a drink?"

"Preferably whiskey."

Jo nodded and poured out two glasses of whiskey. The two of them sat down and drank. Jo began to feel woozy as Susan quickly downed her glass. "How are you not at least buzzed yet, Doctor?"

"I'm more used to it." Susan smiled. "You remind me of a couple of friends I had back in my universe."

"Really?"

"Yeah. Good people. They were workmates with me at Sainsbury's. You have no idea how tedious it is to stack trolleys for a living."

"The Doctor stacking trolleys at Sainsbury's." Jo sniggered. "You'd have to be a fugitive in hiding to willingly go for that." Susan lost her smile and looked down. "...oh, you were hiding."

"And I got caught. It's a miracle I'm still alive at..." Susan stopped as she heard a distinctly mechanical buzz. "Duck!"

A mechanical fly crashed through the window as Jo ducked down. The fly turned its attention to Susan, ready to fly forwards with great speed, but Susan dodged the fly, drank the rest of her whiskey, and trapped the fly under the glass she drank it from. She then got her sonic screwdriver out from one of the pockets of her hung-up coat and used it on the fly, short-circuiting it. "What the hell was that?" Jo asked.

"A Gallifreyan Temporal Eradicator Fly." Susan replied, "If it bit me, I would have been erased from history altogether. We'll need a way to get rid of it, though."

"You've already shorted it out. How is it going to come ba..." Jo noticed the fly manage to turn itself back on. "...how?"

"Good old-fashioned Time Lord tech."Susan quickly removed the glass and smashed the fly with her palm, then smashed it into smaller pieces as it hit the floor, finally crudely separating the remains. "Jo, you get a brush and shovel, I'll get another glass. We'll need to stop it from regenerating."

"And it can't regenerate when it's all split up?"

"Yes."

One half of the fly was swept up by Jo and dumped into the bin at the back garden, while the other half was gathered by Susan into another glass and thrown out the front door. Susan was finally freed from the punishment the Time Lords placed upon her.

Back at UNIT, Shirley got the cannon to the Doctor, who had the battery for it in her hand. "Ready to go, Doctor?" Shirley said as the crew in the testing room was preparing a simulation of the Time Vortex, creating a sense and fast wall of wind.

"Almost." the Doctor replied, "I want to ask something."

"Yes, I'm fine, even with the whole possession thing."

"I was actually going to ask about Morris, your successor. I've not seen him since my previous regeneration."

"Oh. He's been busy on an expedition in Egypt for the past three months. Something about a visit from a group called the Thremokans."

"Last time I saw them, I stopped a bunch of people from being blown up in a giant transforming spaceship six thousand years into the future. What are they doing in Egypt again?"

"Morris messaged me about a rumour of a man wearing a raven on his head was haunting their dreams."

The Doctor's face went grim. She knew that the Black Guardian was influencing other species. "I'm ready."

The Doctor knelt a few metres away from the manufactured current. She turned off the safety and then pulled the trigger, shooting out a laser that created an open area that the wind was pushed around. The Doctor flicked a switch on the cannon and shot at the area again, this time sealing it up. Complete success. The Doctor looked to Shirley. "Get Susan back here." she said.

"So it's a success, then?" Shirley replied, "Are we going to get her back to her home world?"

The Doctor's face became one of sheer determination. The quicker she can get Susan back to her world, the quicker she can get prepared for the Black Guardian. "I'm very much sure of it."