Sensing haste was key, and rather than banging on the oak door, the Doctor instead opted for plunging his finger at the doorbell. A dainty tune played out in the hallway but naturally to no answer. The Doctor sighed heavily. "If you wouldn't mind." The Doctor branched out an arm towards the door. Donna smiled and nodded. "Why thank you Mr. Doctor." Donna half curtsied, before violently and speedily raising a leg to the door and kicking it open. "I bet it wasn't even locked." Donna noted, before the two of them entered the house. There was a strange, cold feeling to the hallway, and everything felt empty and hollow. A blue mist seemed to be seeping out from under the closed living room door. "That's never good." The Doctor said, taking the lead and swinging the door open.
Mrs Henderson was slumped on the sofa, her head against her chest and an arm frozen in the arm, a frail finger pointing in the direction of a large blue alien hunched over her. He immediately looked up with both pairs of eyes blanched a poisonous yellow colour. Garth stared at Donna and the Doctor before scuttling on to all fours, his already gangly fingers slightly increasing in size, as he frantically moved around the room, perfectly mimicking the patterns of your average spider.
"I told you he was from Strelis." The Doctor said as an aside. Donna nodded sarcastically, as her eyes followed the scuttling alien. The Doctor moved towards Mrs Henderson and felt her neck. He exhaled heavily from his nose. "Is she...-"
"Yup," The Doctor confirmed Donna's fears. "He's in his feeding period. No doubt he's been doing this for months, but now he's sucked the last bit of life out of her."
"Well, what do we do? And why aren't we arguing with him or something? I like shouting at the bad guys."
"He can't hear us. He's basically purely instinctual at the moment; feeding on what he can, fight or flight if needs be. No point talking to his rational side. If he even has one."
Garth paused for a moment, turned his head slowly, and slowly approached the Doctor. Donna became defensive but the Doctor held her back, and stared closely at the creature. The two locked eyes.
"He at least recognises I'm not human. Not sure what to make of me. Like if you wandered into the forest and found a mushroom, for all you know it could kill you instantly."
Garth stopped moving his head and retreated slightly, letting out a metallic growl as he did so.
"That's right. Time Lord through and through. Ha!" The Doctor declared triumphantly.
"Doesn't really help with what we're meant to do with him."
"Let's just leave him." Donna stared at the Doctor, waiting for the punch line, but the Doctor had already begun to leave the room.
"Wait, wait, you're serious? We leave a murdering alien living in a small town with clueless people."
"Correct," The Doctor pushed open the front door and strode down the path. "It's fully drained the life force from someone and so fulfilled its needs. It's not a threat more than a common housefly Miss Noble."
"Huh," Donna nodded slowly but remained in thought. "If you say so."
"I do. We best be off." The Doctor remarked, hastily heading towards the TARDIS.
Donna stared at the Doctor for a while before casually asking "You wouldn't mind if I used the screwdriver to...check the weather, would you?"
"I don't see why not." The Doctor passed her the sonic screwdriver without a second thought.
Donna ran her nails over the surface, feeling as if she was changing some kind of setting, before squarely pointing the device at the Doctor and blasting out a strong sonic ray. The violent sound crashed around the empty street, sending off a fair few car alarms and causing a nearby streetlight to flicker before exploding altogether. The Doctor stared at Donna, his eyes radiating a vivid blue before returning to their muddy brown. He staggered slightly, rubbing his temple and staring at Donna out of one eye.
"No need for thanks. All in a day's work." Donna exclaimed, flicking the screwdriver in her hands before dropping it and giving it back to the Doctor apologetically.
"Damn Strelian mind puppetry. How did you know?"
"Well to start with I know you well enough to tell when you're acting out of character. And you'd never willingly give me that thing."
"I think you can see why," The Doctor said, pointing at the broken glass on the floor. "I can't afford to pay all these fines."
"Don't we have a little alien problem to be dealing with first?" Donna asked.
"It doesn't look like it anymore." The Doctor said, pointing towards the sky. Donna turned around to see a small, smoking grey ship bobbing in the air before leaving the atmosphere.
"Didn't want to stay and fight, huh? Typical. Do we go after him?"
"I doubt he'll get far. Barely leave the galaxy no doubt. He'll meet his end soon enough," The Doctor stared at the sky for a while before waking from his daydream. "Back to the TARDIS then? Promise I'm not being mind controlled this time." The Doctor gave a wry smile.
"I believe you. I guess we can't solve all of the world's problems eh." Donna sighed and kicked a stone at her feet.
"I'm sure we can solve a few of the universe's though." The Doctor gave a grin and placed an arm around Donna. The two walked down the street, the fiery sun edging below the industrial skyline in front of them. Earth felt so foreign to Donna now, so alien. And yet that one arm around her shoulder made her feel right at home.