"What is it, Jack?" Gwen demanded, staring at the image on the screen.

"I'm not sure – I know what it looks like, but .. it can't be."

Jack was frowning in the manner that informed his team that he knew more than he was prepared to share. Ianto went to roll his eyes, caught Owen glaring at him and stopped abruptly.

"Living or non-living?" Owen asked. "Any life signs, Tosh?"

"Difficult to determine – it appears to be inorganic", Tosh shrugged, irritated at her inability to provide any more information. "But that might be a form of shielding."

"Really helpful – what's it doing there?"

"Looks like it's waiting". Ianto observed. "It hasn't moved since it appeared there."

"Yeah, that's what worries me – the Rift spits out shit all the bloody time, but this looks like a delivery on our doorstep."

"Jack?" asked Ianto with an imploring expression on his face. "What aren't you telling us? What is it?"

Jack turned his attention away from the screen to look Ianto in the eyes, he opened his mouth as if to reply, but closed it slowly once more, shaking his head as if he didn't dare speak the name of the object.

"Looks like we're going to have to go take a closer look, people. Gwen, you're with me, we'll approach it from the direction of the Bay – Owen and Ianto take the lift and don't move off it until I give the word. Tosh – monitor that 'thing' and tell me the second it does anything."

Minutes later, Owen and Ianto were standing uncomfortably close together on the paving slab at the top of the lift, both clutching their handguns and breathing slowly as if worried that the object sat in the centre of Roald Dahl Plass could hear them.

On closer inspection they could see the patterns on the surface of the silver and grey sphere. It was still immobile and hadn't reacted to their appearance a few metres away from where it was sitting near the steps.

A movement from the direction of the Bay caught Ianto's eye and he glanced across to see Jack's shoulder disappear from view as he darted behind one of the pillars as it changed colour from blue to purple.

It was then that the sphere started to move, slowly rotating on the spot as if surveying the immediate area. The fact that is was aware of their presence was indisputable. As was the fact that it was not fooled by the perception filter at the top of the lift.

"Ianto, Owen - get down – now!" screamed Jack as he dashed out from cover, firing at the sphere. "Gwen – get outta here!"

The bullets ricocheted off the surface of the sphere, having no effect on it whatsoever. But Jack knew that, he was just hoping – in vain – that he might be able to distract it long enough for Ianto and Owen to get clear.

They'd responded by firing as well, following Jack's lead, even as the lift began its slow descent.

The sphere rose up from the pavement, and headed directly towards Ianto and Owen. As it hovered over their heads, razor sharp blades emerged from within and a red laser beam shot through the air. Ianto ducked and rolled off of the slab to avoid being hit by the laser, which struck the water tower before being deflected harmlessly towards the Millennium Centre.

Jack ran recklessly across the Plass – he thought they'd be safe. He hadn't wanted to believe his eyes – but he knew exactly what that thing was.

His self-recriminations were brutally pushed aside when he heard the scream and saw blood spray in an arc as the Toclafane launched its deadly attack.