The central column was slowing its rise and fall.

'Jo,' said the Doctor gently, 'we're about to land in England - in your time. That all happened three thousand five hundred years ago...'

Once again Stuart was calling out the readings, 'Three five, four zero...'

'Increasing power,' said Ruth.

Suddenly another sound drowned out the TOMt.i.t noise, and a blue police box appeared in a corner of the lab. The Doctor and Jo Grant stepped out.

'Suffering monkeys!' said Stuart faintly.

Ruth was too absorbed in her experiment to notice. 'Now concentrate, Stu!' she called. 'Isolate matrix scanner.'

'Check!' He returned to the power readings. 'Six zero, six five, seven zero...'

'See if it's working, Stu!'

Stuart ran to the window and Saw that the Brigadier and his men were back to normal. He could hear the Brigadier shouting orders. Stuart turned back from the window. 'Yes, it is!'

'Good!'

The Doctor studied the power readings. 'It to be working a bit too well.'

'It's running away,' shouted Ruth.

'Everybody get down!' shouted Stu. 'It's going to go up!'

They all took cover as the TOMt.i.t console overloaded and blew up.

In the absence of the crystal however, the was nothing more serious than a loud bang, a shower of sparks and a lot of smoke.

Ruth got to her feet and studied the shattered console.

'You'll have to start all over again,' said Jo Ruth shook her head. 'I couldn't, not without the Professor. Just as well I suppose.'

'Well, it's done its job, thanks to you,' said the Doctor. 'Everything's back to normal.'

As if to prove the Doctor's point, the Brigadier burst into the room, revolver in hand.

'Stand still everyone.' He broke off, staring round the somewhat unexpected group.

'Er - where's the Master?'

'A very good question, Brigadier,' said the Doctor.

'Ah, Doctor, glad to see you're back. And Miss Grant...'

The Brigadier suddenly registered Jo's Atlantean costume. 'Miss Grant, what are you doing in that extraordinary get-up?' Without waiting for a the Brigadier went on, 'And where, for heaven's sake, is Sergeant Benton?'

Stuart clutched Ruth's arm. 'The baby! We forgot the baby!'

Sergeant Benton arose from behind the TOMt.i.t console. He had been restored to his full age and size, and he was wearing nothing but a very inadequate improvised nappy, and an embarra.s.sed smile.

He looked around the circle of smiling faces, and said plaintively. 'Would someone please tell me exactly what's been happening around here?'

And that too, thought the Doctor, was a very good question!