Sorry for the little delay, guys, my laptop has been borrowed by pretty much every member of my family in the last few days so I've been forced to work on a new one that I don't understand. Oh well. Here's chapter 4 – please follow, favourite and review!

The Doctor beamed at Lilly. "Oh, I was just in the vicinity and thought I'd pop in for a chat...discover why you're all bashed up like that. How is Canton? And your mother?"

"They were both fine, the last time I saw them. Doctor, you have to help us. You have to discover what's on that ship. Do you think you could –"

"Whoa, whoa, hang on here," interrupted Kirk. "Who the hell is this guy?"

"I'm the Doctor, Time Lord, from Gallifrey. Very old, very clever, and very-"

"Yes, we get the picture," said Lilly, rolling her eyes. "Captain, the Doctor is an old friend of my family's. Doctor, this is Captain Kirk of the U.S.S. Enterprise. Play nice."

The Doctor straightened his bow tie. "I always play nice."

"Doctor, do you think you could get aboard the ship that's firing on us?"

"Well, yes," said the Doctor nervously, as the lights flickered behind him, "Because I'm already on it."

"What? Why?"

"I thought I was landing on your ship, Delaware! These Star Fleet ships, they're all the same, no personality..."

"Oi!" said Scotty indignantly. "My girl's got personality in spades."

"Doctor," said Lilly with a sigh, "My surname is Moscovitz. Someday you're going to have to accept the fact that my mom got married."

"Never."

Lilly groaned. "Listen! We need you to find out what's on there. The ship can't take another beating like that."

"I know what's on here, Delaware. How to defeat them – that's another matter. I –"

The lights behind the Doctor flickered again. "I need to get off here. They're coming for me. If they find me –" The lights flickered off completely and the viewport went dark.

"Doctor? Doctor!"

"I'm trying to get him back," said Lieutenant Uhura, "But I think...everything is down. That whole ship's gone dark."

Then Lilly's phone went off. She checked the screen. A text read:

[Come along, Delaware! I'm in the cargo hold. Hurry, I think they've followed me. Bring the captain and any intelligent people you can. Geronimo!]

Lilly frowned at the screen. "That's weird. I didn't know he could text."

Captain Kirk leaned over her shoulder and read the screen. "OK. We should get going. Spock, Mr Scott, Mr Chekov – you come with me and Lilly to find the Doctor. Sulu, Uhura, Bones, you hold the fort up here."

When they reached the cargo hold, they found something they weren't expecting.

"Is that...an old police box?" asked Scotty incredulously. "That's a Time Lord ship?"

The Doctor opened the door and stuck his head out. "This is a TARDIS, Mr Scott," he announced proudly, "And...I'm afraid she's brought something nasty onto this ship."

Lilly shivered. "What?"

"The –"

Suddenly, the whole bay was plunged into darkness.

Lilly felt a hand grab hers, and the Doctor voice whispered in her ear: "We need to get out. Now. Into the TARDIS."

Lilly felt for Pavel's hand and tugged him along, hoping that the captain, Mr Spock and Scotty were following. The door swung shut behind them and they blinked as they stepped into the golden interior.

"Bloody hell...it's...it's..." stuttered Scotty.

"Bigger on the inside," breathed Pavel reverently.

Lilly grinned at the Doctor.

Kirk was listening at the door. "There's nothing happening out there," he said, frowning.

"Yes, there is," said the Doctor gravely. "I'm sorry, Captain...I'm so sorry I brought these creatures onto this ship. I swear to you, I didn't intend to. But now, we have to move quickly." He pulled a few levers and the TARDIS lurched.

"What are you doing?" asked Pavel curiously, limping over to stand by the Doctor. "That looks pretty complicated. How do you fly her?"

"This machine is quite incredible," said Spock simply. "I assume she somehow uses the Time Vortex to fly?"

"Do you mind if I...take a look around? She's magnificent, really," grinned Scotty.

The Doctor chuckled. "Good choice with this lot, Lilly."

When the TARDIS landed, they were greeted by worried faces on the Bridge.

"Captain, every other deck has gone quiet. No lights, the computer is down...everything's gone," said Sulu nervously.

"I can't get a message through to anyone," said Uhura. "We're turning into a ghost ship, sir."

"This is not good," said the Doctor. Striding into the centre of the Bridge, he looked around. "We need lights pointing out, at every entrance. We have to fortify this place before we do anything."

"Hang on," said Kirk, "I think you'll find I'm in charge here."

"But I know what's out there."

"You still haven't told us what it is," Lilly reminded him.

The Doctor turned to her with a grave face. "It's the Vashta Nerada, Lilly. The Piranhas of the Air."