It had been a very long day, well, actually a long three days

Caught in a cave, with no escape , until the Doctor had bargained themselves out.

Donna and the Doctor were exhausted, the first thing they had done when they reached the TARDIS was to have a good feed , deprived of food for three days, and then shower to get all the dirt and smell of themselves.

Now Donna had fallen asleep, in an armchair, in deep sleep. Right in the middle of Harry Potter and The Chamber of Secrets they had been watching on the large screen. The Doctor, who had a quick cat nap, was feeling refreshed.

And was feeling mischievous. He was bored.

He glanced at Donna's peaceful face and smirked. She was dead to the world , there was no way that she would know what he was up to.

The Doctor got to his feet, searching for that black marker he knew he had somewhere in a drawer in his office, soon he returned to the media room , Donna was still dozing and let out a snore

He hesitated, knowing what Donna's reaction probably would be when she realised what he had done, then shrugged.

Ever so slightly, he edged towards Donna, the marker in his hand, and leaned over.

'Mmm' Donna mumbled, and he stopped, likely to be caught, backing off, ready with an excuse, then she snored again.

When the marker touched her skin, he waited for a flinch , but it didn't occur. He smirked as he drew a moustache and beard on her face, trying not to laugh out loud to stir her. Admiring his handy work, he backed off out of the room and as soon as he was fa away as possible, let out the laughter he had been holding back . He was ready for the back lash, and he didn't care.

'So totally worth it' he thought.

He managed to hold back a smirk when Donna woke, oblivious to the fact that her face had been drawn on. The charade lasted until Donna was peering into the mirror when she was getting ready for bed. The Doctor heard her yells , at him .

'OI SPACEMAN , WHY DO I HAVE A BEARD AND MOUSTACHE ON MY FACE! NOT FUNNY YOU MARTIAN ! IT BETTER NOT BE A PERMANMENT MARKER! '

The Doctor gulped in shock when he checked the marker.

'Oops' he muttered in shock, when he read ' Permanent' in small bold print.