So did the sketch. The exterior of the box was a lot like the portal control Henry used the first time he translated to the Realm. The drawing of the interior made no sense at all. There was provision for a battery, one of those expensive, long-life little efforts that powered digital watches, but beyond that Henry couldn't follow it at all. He stared for a long time, then decided he didn't have to follow it. All he had to do was make it. It was like a television set. You didn't have to know how it worked, you just had to know how to switch it on. If he followed Mr Fogarty's plans exactly, then the portal should open when he pressed the button.
The problem was Henry had never made an electronic device before. He'd learned a bit about circuit diagrams and components at school, then promptly forgotten most of it and switched class before they got to putting things together. But he had built working model cardboard sculptures – how much more difficult could electronic stuff be?
It turned out not to be difficult at all, but it took more time than Henry had expected. What made it easy was Mr Fogarty's habit of making little doodle sketches of every necessary component. The doodles crawled all over his notes so that even when Henry didn't understand terms like gate transformer, he had a picture of what he was looking for.
A lot of the parts he needed were stored in the kitchen drawer, while others were out in Mr Fogarty's shed. Henry felt a twinge of guilt as he collected some of them – they were items he'd stolen from his school for Mr Fogarty when they had been trying to build a portal to get Pyrgus back to the Realm: they'd have to go back again before school opened after the summer break.
It was only when he started to put the pieces together than he discovered there was a component missing. Henry went on a major search after that, but without result. What he was looking for was labelled 'biofilter' in the notebook: a small, flat disc apparently made by fusing two layers of metal to make a sandwich with a third, then attaching a tiny looped aerial. There was nothing like it in the kitchen drawer, nothing like it in the shed. Henry went on another search of the whole house again before deciding that whatever a biofilter was, Mr Fogarty didn't have one. He leafed through the notebook to see if there were any instructions for making one, but there weren't. What to do now?
Henry pored over the design diagram trying to figure what the bio thing actually did. As far as he could see it did nothing – it didn't even seem to be attached to anything. But then again, a lot of the device was like that. There was even a circuit that wasn't a real circuit, but a drawing of a circuit. Mr Fogarty had labelled that one 'psychotronic pathways' and added a note saying, 'Insert right way up in relation to transistor 8'. Henry decided to leave the bio disc thing out altogether. He wasn't at all sure this was wise, but he didn't see what else he could do.
He started to put the device together using an electric soldering iron he found at the back of the kitchen drawer. It was slow, absorbing work, very much like model-making, and it was dark outside before he realised he was very hungry. He left the half-finished device (which didn't look half as neat as the things Mr Fogarty made, but what the hell – it was his first attempt) and went in search of something to eat. The fridge was empty as usual, except for the familiar pint of curdled milk, but he found a Birds Eye shepherd's pie in the chest freezer in the laundry room. Cook from frozen in the microwave, Captain Birds Eye told him cheerfully by means of a cartoon bubble.
Mr Fogarty's microwave was pristine. Somebody had given it to him and he had never used it because of something he called 'radiation leakage'. Henry removed the outer packaging, bunged the shepherd's pie inside and set the timer for seven minutes. Then he took a tin of baked beans from the cupboard (Mr Fogarty always had plenty of baked beans) and heated them in a saucepan on the gas stove. By the time the microwave pinged, the beans were bubbling merrily. He plogged the lot down on a willow-pattern plate and ate his meal with gusto.
Since it was clear he wouldn't have the device finished in the next hour or so, he decided to stay the night. He felt a wonderful surge of pleasure at the decision. The sense of freedom was astonishing. He didn't have to answer to his mother. He didn't have to listen to his rotten sister. He could stay out all night if he damn well liked. They wouldn't even notice he was missing.
Henry's sense of freedom was gone in the morning, replaced by something close to panic. He'd had the weirdest dream about Pyrgus. They were running from a small army of rotting zombies who loped along a city street with bits falling off them. Blue was in the dream as well. She followed after the zombies with a dustpan and brush, sweeping up the bits. As she worked, she kept calling after them, 'What kept you, Henry? What took you so long?'
Whatever about the zombies, he could believe that was exactly what Blue must be saying now. There was trouble in the Realm, she'd asked Henry for his help and he'd promised to follow on as quickly as he could. She'd probably expected him within an hour or two at most. He grabbed the soldering iron without even bothering to have breakfast.
He finished the portal control around lunchtime, with one break mid-morning to fry up two hamburgers he found in the deep freeze. It looked a real mess as it sat there on the kitchen table – a rat's nest of terminals and wires with an on/off switch too big for the rest of the components. The control Mr Fogarty made was smaller than a mobile phone. Henry's version would hardly fit into a shoebox. He wondered how he was going to carry it about with him, then decided he didn't have to. If he could open a portal to the Realm, Mr Fogarty could always get him back. Or Pyrgus, come to that – there was a portal in the Purple Palace.
He bit his lip, stared at it for a little while, then decided it was time to try it out. Since he'd learned the hard way not to open portals indoors, he carried the device into the back garden and down to the little area of wasteland and rubbish beyond the buddleia bush. It struck him that if he hesitated he'd never have the courage to do anything, so he threw the monstrous switch right away.
Nothing happened.
It was that biofilter thing! It wouldn't work without the biofilter! He was finished. He'd have to go home and wait for Aisling to get back to normal all because of that stupid biofilter!
Or possibly a battery…
Henry felt like kicking himself. The famous biofilter might yet be a problem, but meanwhile it would be an excellent idea to put a battery in his device. He ran quickly back into the house and searched the drawer. There were several batteries pushed in at the back, but none was the lithium button he needed. He ran to the shed, but could find no batteries there at all.
Where are you, Henry? Why didn't you follow on like you promised?
He was so late! He was so long delayed! He glanced at his watch. One twenty-eight. That was nearly – there was a battery in his watch!
Henry ripped the watch from his wrist. He needed a little screwdriver to get the back off, but there were little screwdrivers in the shed. In moments he was looking at a battery that would fit his makeshift portal control to perfection. He prised it out of the watch and carried it quickly outside.
He discovered he was breathing heavily as he pushed the battery into place. He checked the contacts and decided everything was ready. Then he had a small heart-thumping panic: there was no way this thing was going to work without its biofilter. The biofilter just had to be the most important component in the entire thing. Dear heaven, what was a biofilter?