Rhinoceros by Colin Forbes

Roy Buchanan and ask him to start a search for her. Now . . .'
    He was on the phone when Harry Butler came in. In his large fist he held a folded sheet of paper. He sat down while Tweed spoke to Buchanan.
    'What's that piece of paper you're holding?' asked Paula, as curious as a cat.
    'Wait. Then you'll see.'
    He handed the sheet to Tweed the moment he fin ished his call. Sitting upright, he spoke as Tweed opened the sheet.
    'Remember that chopper that followed us back from Alfriston? It did look to me as if it had taken off from Lord Barford's estate.'
    'How high would you say it was when you saw it?'
    'At a guess, about a thousand feet.'
    'Was it gaining height?' Tweed persisted.
    'No, cruising along.'
    'Then it could easily have been the chopper we saw grounded at Rondel's place.'
    'If you'd read my report. Just extracts from the file we have on Lord Barford.'
    Tweed, surprised that Harry should have thought of checking the file, read the short report twice. Then he leaned back and stared at the ceiling. He was frowning.
    'That was clever of you, Harry,' he said eventually. 'You left out that, after leaving the Army, Bernard Barford was chief of Special Branch for a while.'
    'Didn't seem relevant.'
    'I agree. What is relevant is that he owns a Sikorsky helicopter, commutes to London in it. Must have a pilot - I know he's never flown a plane in his life.'
    He looked at Paula. She told him Monica had typed the report. He transferred his gaze to Newman.
    'That means,' Newman remarked, 'we don't know which chopper tailed us to London, doubtless reporting our whereabouts - so that gunman could be waiting for us.'
    'I could get Art Baldwin up here,' Paula suggested. 'Then we can open his envelope of pics, the ones I took. He'll go mad if I open it before he's with us.'
    'Heaven save us from boffins,' Newman snapped. 'Although I will admit Art is undoubtedly the best inter preter of photos in the country.'
    Tweed nodded to Monica, who phoned for Baldwin to come up. Within a minute there was a gentle tapping on the door. Tweed called out, 'Come in.' The door opened and a small man whose face vaguely resembled a squirrel's crept in. He wore thick-lensed glasses. Paula smiled and waved for him to come over. As she was opening the large envelope, Art spoke in a squeaky voice.
    'I've printed the photos you took in Sussex. Original size and various enlargements.' He took a folding magnifying glass from his pocket. 'Very intriguing. I have comments.'
    Everyone in the office, except Monica, got up, gathered round Paula's desk. She spread out the prints. She had used the new camera, invented by the basement boffins. At night it took very clear pictures without needing a flash.
    'The chopper in the background,' Newman said. 'Can we bring that up more clearly, please?'
    Art unfolded the small boxlike magnifying glass, pos itioned it over the helipad area. Newman peered down at it, grunted. Then he straightened up and whistled before he spoke.
    'That, ladies and gentlemen, is a Sikorsky.'
    'So,' mused Paula, 'that chopper which followed us . . .' She broke off, remembering Baldwin was with them. She had been going to say 'the helicopter could have come from Rondel's place.'
    'I'm also deeply interested in that mast with a complex dish at the top of it,' Tweed said.
    'Fred,' Baldwin began, 'who, as you know, is an expert on communications systems, said that dish is something advanced, something entirely new.'
    He placed the magnifier over the dish. Paula sensed that Art was nervous, wasn't going to say anything more. She looked at Tweed and realized he'd had the same reaction. Newman peered at the image and shook his head. It meant nothing to him.
    'That was it?' asked Tweed.
    'Fred did tell me to keep his other conclusions from you until he'd completed his researches,' Art replied.
    'So what is he keeping secret? I need to know now,' demanded Tweed.
    'He is wondering whether the dish is designed to operate laser beams of enormous power that