The crack on the ceiling was very fascinating, thought Doc Brown as he sat in silence on the tattered old arm chair by the window sill. So long, so big and so….

"DOC!"

Doc quickly snapped out of his crack obsession and turned to see his friend Marty looking at him urgently.

"DOC, WE'VE GOT TO GET YOU OUT OF HERE!" He shouted aloud.

One of the other elderly residents of the retirement home, a man Doc knew as Mr Styn, glared at Marty intensely.

"OI! Stop with the noise, you yob!"

Marty didn't listen.

"What's the panic?" Doc asked suspiciously. "I was just thinking about the truly fascinating dimensional principles of a crack o-"

"The sign outside said 'Tannen Retirement Home'. I think Biff owns this place!" He replied.

As Doc gasped in horror at the news, an unpleasant odour entered the room as Biff appeared carrying a walking stick and, noticing Marty, scowled unpleasantly.

"What are you doing here, squirt?" He shouted threateningly.

Marty looked around frantically for a quick way of getting Doc out. By the door sat a wheelchair; a quick nod of the head indicated to his friend that that would be their method of escape and Doc swiftly walked over.

Biff watched as Marty wheeled Doc out of the room.

"AFTER THEM!" He cried and the elderly residents followed Biff out the door.

Initially, it was a relief to get away from the retirement home; that was until Marty glanced round to see the elderly people chasing after them. Led by Biff.

"HOLD ON, DOC!" Marty called as he spurted down the road with the wheelchair.

The wheelchair sped down at such speed that Doc nearly fell out twice within a space of minutes. But the retirement home crew were gaining on them fast.

"I didn't know elderly people could be so fast!" Marty exclaimed. "What's fuelling them? The Sound Of Music soundtrack?"

"The number of times I saw that on the TV were more than the times I've got my childrens' birthdays wrong!" Chuckled Doc.

Suddenly, Marty blacked out as he began to remember more…

Marty ducked as a holographic shark attempted to eat him.

A game of Wild Gunman proved to be a fun distraction for Marty from all the time-travelling currently present in his life.

"I've got a warning only you can take," The skinny man in the blue box warned as Marty hung silently in the sky.

As the flow of memories stopped, Marty found his sight return. But it wasn't a welcoming sight to return to. To Marty's horror, neither Doc or the wheelchair were anywhere to be seen.

And Biff and his army of elderly people were closing in on him.