He knew Jenny had gone to the shop to get his grandfather to sign more advertising contracts for the shamefacebook site, and he knew the police had now reduced their patrols around the building to the infrequent level that had preceded the arson attack. It was only as he jostled impatiently in the crowd waiting to cross Lai Chi Kok Road that he finally rang and discovered the true source of Jenny's consternation. This was, however, only fractionally less worrying.
As he stood in the study of Jenny and Sam's family home, Ethan was still getting his head around the news. "So we've been hacked?"
Jenny nodded impatiently. "I told you. Look, I found this e-mail among the contracts. My idiot brother didn't notice it."
"Is it serious?" Sam asked sheepishly.
"Is it serious!" she demanded, handing Ethan the hard copy. "It's like finding rats in the fancy restaurant you've just opened."
The message was a complaint to the creators of shamefacebook from a hurt and angry girl. She had posted a confidential and heartfelt apology on the site for an insensitive remark she'd made to a friend whose beloved pet had just died. But when her upset pal had logged on, what she read was: "Boo-hoo - get over it, you big baby."
Ethan winced. "Oh, no." As someone who had made more than his fair share of faux pas, he had conceived the site as a vehicle for reconciliation, not a means of spreading more pain.
"We've had more complaints since," Jenny told the shell-shocked Ethan. She kicked the table in frustration. "I should have known. Once a social site gets even a little bit popular, all the cranks come out of the woodwork to try and hack it."
Sam retreated in response to an alert from his smartphone.
Jenny pointed at her open laptop. "I've made a list of all the new profiles created since the first complaint. We can go in and see if any of them have been corrupted."
Ethan shook his head. "No, we can't. We have to respect the privacy of our users." He thought for a moment. "We'll just send everyone on your list an apologetic e-mail explaining what's happened and asking them to ignore anything ... er ... inappropriate."
As Jenny scoffed at the inadequacy of this gesture, Sam told them about the message he'd received. "It's from one of our advertisers. A news report has just claimed shamefacebook has become a platform for bullies." Ethan put his head in his hands.
"I've changed the rights so nobody can amend the database," Jenny told him. "But that means the site is no longer fully functional. And until we find the backdoor the hackers have installed in our system, we're still wide open to more attacks."
Much later, after they'd failed to trace the location of the malicious code, Ethan was saying a weary good night to Sam and Jenny, when he noticed a hooded figure standing across the road watching them. He turned to his friends. "Who's that?"
By the time Sam and Jenny looked out, however, all they could see was a deserted street.
When Ethan got home, Mum and Grandad were still up.
His mother glanced up from her newspaper. "Studying late?"
"Uh-huh," muttered Ethan. "Goodnight."
She smiled. "Goodnight, Sui-man."
His grandfather followed him into his room. "Did you see what she's reading? It's the jobs page."
"What?" Ethan exploded. "After all the warnings from the doctors?"
"I know, but ..." Grandad shook his head. "Anyway, how are things with the website? Sam's sister seemed in a bit of a panic earlier."
Ethan couldn't bring himself to tell the worried elderly man the truth. "Fine. Just a little technical problem."
But as Ethan lay in bed, the financial implications of this "little technical problem" began to sink in. If shamefacebook failed, he had no idea how the family could make ends meet - and he couldn't bear thinking about the likely consequences of Mum going back to work.
Another thought also kept him awake. On the list of recently created profiles on the social site was one set up by Kieran O'Shea.
It had taken a real effort of will for Ethan to respect his own rules on privacy and not sneak a peep. He desperately wanted to know if Kieran was trying to patch things up with Maya - and what her response had been.
The next day brought more bad news. Two of the advertisers on the site had cancelled their contracts in light of the negative publicity.
And the publicity was most definitely negative. When he arrived, Ethan found half the school talking about "the shame of shamefacebook".
By break time, however, lack of sleep had caught up with him. He was awoken only by the sound of the classroom door opening.
"I won't close it in case you need to run off again." It was Maya.
Ethan forced a bleary-eyed smile. He wanted to ask her about Kieran, but there were other more pressing things that needed saying. "Before I left you yesterday, I was trying to explain why I've been so flakey."
Maya smiled. "And ..."
"It's complicated," he continued.
"I thought it might be."
Ethan hesitated for a moment, and then the words came tumbling out in a breathless torrent. "I'm doing what I'm doing to support my family, but I've promised my Grandad I wouldn't talk about it as Mum would worry too much if she found out, and she can't cope with the stress and ..."
Maya squeezed his hand. "It's ok."
Ethan looked into her eyes. "No, it's not. And I am sorry."
Maya shook her head. "Don't be. And don't worry, you don't have to break any promises. Your friends will be there for you whatever."
As Ethan hurried through the rush hour streets that evening, on his way to Sam and Jenny's and the resumption of the hunt for the hackers' code, he became aware that he was being followed.
From the hazy shop window reflections, Ethan could see that when he slowed his stalker slowed, too, maintaining a constant distance from him. At a road junction, Ethan stole a glance back ... although he was now marking time in the midst of the crowd, Ethan was sure that it was the same hooded figure that had spied on them last night.
The attacks on Grandad's shop, the site getting hacked ... and now this. It seemed he and his family were surrounded by threats - and Ethan couldn't help wondering if some or all of them were linked. Beginning to feel truly afraid, Ethan picked up his pace.
To be continued next week