On the Wednesday after the U-boat sighting at Port St Johns, Digger O’Brien met again with his non-commissioned officers to check what progress they had made. Nothing, seemed to be the answer. Inquiries around the towns and villages had shown up no suspicious strangers. Nor could these NRV members think of anyone at all in their area who might be the sort of “mole” George Trebble was talking about.

Then Digger noticed George himself jumping up and down like a schoolboy who had done his homework. ‘What have you got, George?’ he said.

‘Maybe a suspect, sir,’ said Trebble. ‘Can we talk in private?’

‘No, George,’ Digger O’Brien said. ‘If we can’t trust one another here, we may as well go back to our tiddlywinks.’

So George Trebble proceeded to tell them all about Nick Mostert, about the fracture Ian Ross apparently was unable to find and his plan to get the young Moore to question Mostert face to face.

‘Good work, George,’ said Digger. ‘But that’s a hell of an allegation and it must not go any further than this room. In the meantime, let’s see if we can watch this Mostert bloke. See where he goes. See who he talks to.

‘What does he drive anyway? Oh, that old De Soto with the cage on the back. Well, according to Ginger Southwood, that size vehicle could fit those tracks. Although he thinks it’s more likely to be a truck. So I also want you chaps to get together and make a list of all the trucks you can think of in this area.’

‘Herman Weisse’s got that Dodge,’ said Arthur Klette. The auctioneer-licence examiner was one of two lance-corporals in the NRV. And he knew local vehicles. ‘Gerald Wilson’s got an old Chev van. And Leon de Witt has got his milk delivery truck. That’s about it.’

‘There’s the black Ford truck of the Buhls,’ said George Trebble. ‘But I haven’t seen anyone driving it since Fritz left. It just stands there at the back of the garage.’

‘See how many others you can think of,’ said Digger. ‘A lot of traders have trucks. But if our spy turns out to be a trader, I’ll be a monkey’s uncle.’

A different manner of surveillance was already in place around Nick Mostert, as he walked up York Road, having dropped some chickens off with the butcher. Billy Miller was matching him pace for pace on the other side of the street.

Mostert turned into the BV (for Best Value) Bazaar and spent ten minutes chatting to the owner, George Kolivos, who occasionally bought eggs from him. When he emerged, Billy was staring at the shop from the opposite pavement.

Nick Mostert changed direction and walked back towards the Grosvenor Hotel. The boy did the same. Mostert crossed the road and confronted him.

‘Are you following me, Billy?’ he asked. ‘You are Billy Miller, aren’t you?’

Billy Miller glared. ‘Yes,’ he said. ‘No, I mean. I’m not following anybody. I’m just waiting here for a friend.’

Mostert laughed, patted Billy on the shoulder and walked off.

A few minutes later, in the Grosvenor bar, Pondo Harrington told him that a pilot whose parents lived in Umtata would be in town that Friday night and had expressed a wish to meet him, to exchange war experiences.

‘Why me?’ asked Mostert.

‘Well, young Moore’s with Twelve Squadron at the moment,’ said Pondo. ‘Just recently joined. So you should have lots to talk about.’

 

The public library, a block and a half away from the O’Brien home in Owen Street, was Danny’s favourite place, milk bars and the Metro Cinema notwithstanding.

Even when he wasn’t changing his library books, he liked to go in and browse through the children’s section, looking at the books he had yet to read. He liked their smell, but also the fact that they were there, for him to enjoy at some time in the future.

But what afterwards? He paged now through the library books his father took out. The Saint and Bulldog Drummond looked interesting, although the action seemed slow-moving.

Billy Miller walked in. They had arranged to meet in the corner where the picture books were, the furthest point from the librarian’s desk.

‘How did it go?’ Danny whispered.

Billy shook his head. ‘He saw me,’ he whispered back.

‘How?’

‘Well, I tried to watch him from the town hall gardens,’ said Billy, ‘but then he went down to the butcher so I had to come out into the street.’

‘D’you think he knew you were following him?’

Billy nodded. ‘He asked me if I was. I said I was waiting for a friend. He thought it was a big joke.’

‘Maybe he’s on the lookout for people following him because he is that spy,’ said Danny. ‘We’ll have to be more careful. It’s going to be hard.’

Walking back along Owen Street, they encountered Alan Dewes, looking like the cat that swallowed the canary. In his hand he had a small torch. ‘You two!’ he said. ‘Come and see what I’ve found!’ He turned and began to trot down the hill.

Behind Owen Street was a lane that led up from the O’Brien home to the bottom fence of the Royal Hotel. The large house where the Dewes lived was midway between those two points. On the opposite side of the lane was the town engineer’s yard, a place of bulldozers, a steamroller and trucks.

That was where Alan was bound. Danny and Billy followed through the back gate of the Dewes’ property. They climbed through the strand fence of the yard and made their way to an open area where Alan stopped. Ahead was a half-open manhole cover.

‘Help me move this more,’ he said. ‘It’s quite heavy.’

The boys shifted the cover to reveal an opening several feet in diameter. On one side, metal rungs led down into the darkness. Alan turned on his torch.

‘It goes to the drains!’ he said. ‘Let’s go and see.’

Danny and Billy followed him down the ladder and the three were amazed by what lay below. A warren of passages led in four directions. Their outline could be seen by the occasional shafts of daylight emitted through gaps just below the concrete roof. Since it had not rained for several months, the floor was dry and surprisingly clean.

They chose one passage. Billy took Alan’s torch and led the way. After an incline, the passage flattened out to a T-junction. Ahead was another metal ladder. Billy climbed it. ‘Wow!’ he exclaimed. ‘We’re right under the pavement!’

The other two coaxed him down to take turns to look. ‘I can see the Clarendon Hotel!’ said Alan.

‘That’s right,’ said Danny. ‘That means we’re on the corner of Owen and Sutherland Street, right under the Metro!’

They retraced their steps and followed the tunnel past the manhole where they had climbed down. It led to a dead end. But to the right was another patch of light. It was the drain just below the O’Briens’ house.

‘There’s my dad’s car outside,’ said Danny. ‘It must be home time.’

‘Let’s come back and explore tomorrow,’ Alan said. The boys climbed out of the tunnel, dusted themselves down and carefully replaced the manhole cover.

‘How did you find this place, Alan?’ asked Billy. ‘That was darned clever.’

Alan had been looking for old ball bearings in the town engineer’s waste bin that contained metal scraps. The boys substituted large ball bearings, when they could be found, for the real marbles that were fast running out.

Alan’s search revealed six ball bearings in a broken brace but when he tried to prise them out, one had fallen through a vent in the manhole cover. ‘So I shifted it a bit and saw that deep hole and the ladder!’

The next afternoon, the three went back with a torch apiece. And then they discovered an even more marvellous thing. The network of drains ran under pavements on both sides of all the streets in the centre of the town, with regular gaps in the gutters where they could see out. High up, near the ceiling, the individual road names were stenciled in black paint.

Sometimes there were metal-runged ladders as they had encountered the previous day but usually the drain floor below these gaps was high enough to enable the boys to stand on tiptoe and peer out.

It was an expedition of wonder and excitement. At one point, Billy looked and said, ‘Hey! I was standing right above here yesterday. There’s the BV Bazaars! Old Mostert would never have seen me if we knew about these tunnels then!’

‘That’s right!’ said Danny. ‘We can follow him from down here in future. Wherever he goes around town. Wow!’

They walked east along Sutherland Street and beyond the Royal Hotel. A car was parked in a grove of trees on the empty lot below the Catholic Cathedral. A couple were in the front seat, in a close embrace.

‘What are they doing?’ asked Alan.

‘Kissing,’ said Billy Miller. ‘It’s Mrs Howlett and Mr Fuller from the jail.’

‘I didn’t know they were even related,’ said Alan Dewes.

They watched the two adults until they became bored, and then turned back along the drain to Owen Street. Harry Spring was walking with his pogo-stick motion towards the Masonic Hall.

Billy cupped his hands and started to moan in a deep voice. ‘Harreee!’ he intoned. ‘Harreee!’ Harry Spring rose a foot in the air and almost fell over.

During break at school the next day, the three of them told Charles Perkins about the underground maze and together they drew up a plan of action. It didn’t involve Steyn Mostert, whom they thought would still be embarrassed because Nick Mostert was his relative.