They then took me to a police station where they confiscated my papers.

At the time I pressed them about what I had done wrong. Still no one answered me. So all I could do was sit in the detention area within that police station until night time. Someone came over to ask me for my name, but my ID card and papers were all confiscated.

That night, I sat on a chair for criminals for the whole night and didn’t get to sleep a wink. Of course they provided me with food. It was at around 7am in the morning – very early – when people from the police station and the people who took me away came over with breakfast. Then at around 7am, we got on a northbound train.

I was covered up the whole time. They blindfolded me and put a cap on my head and basically bundled me up.

While on the train, I would sometimes peek out – what did I do? Where am I going?

The ride was 13 to 14 hours long. Then I found out that they had taken me to a place in Ningbo.

We got off and they took me by car to a place 45 minutes away ... to a large building. They took me up to a room on the second floor. Then they changed my clothes.

That night I kept asking them what I did wrong, but they never gave me an answer.

The next day around the afternoon, someone came to interrogate me.

They still did not tell me exactly what I did to deserve being detained. I was given a document to sign. There were two clauses: one to promise not to contact my family; two to promise not to hire a lawyer. Under those circumstances and in reality there was no one I could ask for an opinion – I was all alone – so I could only sign the document.

Under those circumstances, there was no choice but to sign it.

Then they started to ask me what my position was at the bookstore. I said I used to be the boss – it was Causeway Bay Books. They asked me why I kept on helping mainlanders mail books to the mainland. They investigated the past operation of the bookstore, what was the bookstore’s relationship with the publisher and my previous relationship with the publisher.

Of course I said we were a legitimate bookstore. Under Hong Kong law, we were a little bookstore with normal operations. In Hong Kong it was legal.

At the beginning, they said that because I was delivering or mailing books illegally to the mainland, I had broken their law. But they said that books published in Hong Kong could not be mailed or taken to the mainland and to do so would be illegal. Then they said they might prosecute me because I had broken their law.

Before I mailed books from 2013 to 2015, I brought certain books across the border for readers. They caught me once and gave me a verbal warning and detained me. Back then they said that I had broken the law because I brought those books across the border.

After that, I didn’t dare bring books over. But some readers want to read those books. Hong Kong is a place with freedom to publish and read, so I thought there was a need [for the books]. As it was also to satisfy mainland readers’ needs, I helped them mail books from Hong Kong.

In those cases, it is completely legitimate in Hong Kong and I did not break the law.

So I don’t understand why the action of mailing books in Hong Kong would be counted as breaking their laws.

If they think that I’ve broken Chinese laws, they could launch an official criminal prosecution or a prosecution against me in Hong Kong. There is scope to do this.

Why did the Chinese government choose to suddenly detain me when I was passing immigration – without warning. Of course in the process, they did not treat me badly. I was fed, I could see the doctor and had a place to sleep. But from October 24, apart from the night I spent in Shenzhen and the train ride to Ningbo ...I spent five months in a space that was 200 to less than 300 square feet – 24 hours a day. I was watched over by six teams of two, 24 hours a day.

I want to ask how is this necessary before they prosecute me?

They told me that I was just under “residential surveillance”, but in reality I couldn’t even take half a step outside. I could only look at the sky. I couldn’t get a lawyer, I couldn’t call my family.

I don’t understand how such a big government could treat a bookseller like this, just because they think that he’s broken a law. I hope that relevant Chinese government departments can give us an answer.

I don’t think this is just my personal issue or an issue regarding the right to sell books. This is about the rights of all Hongkongers. [The Chinese government] talks about “one country, two systems”. But my personal experience and that of my colleagues says otherwise.

Did the almighty Chinese government violate “one country, two systems”? We don’t need to argue over it. I just want to see how you [the Chinese government] will answer. I believe that justice is in the heart of the people.

The reason why I’m seeing the media today through Mr [Albert] Ho is because I really have something to say.

I came back to Hong Kong – they allowed me to come back to Hong Kong today.

Several months in they let me go to Shaoguan [in northern Guangdong], where they rented a room for me and intended to keep me there long term. I was there from April until June. It was better there, I had a higher degree of freedom.

Also they got the bookstore to terminate my employment and give me severance pay of HK$100,000 to cover my living expenses. This was something which they did for us and helped with our living expenses over there, as well as a sort of compensation for us.

But for me personally, I did not want compensation. The only thing I wanted was my freedom.

Until the day before yesterday, because I kept on asking to be allowed to return to Hong Kong to see my family and visit my teacher, they finally allowed me to come down after a lot of negotiation. But they had one condition, which was that I had to bring back to the mainland a hard disk [Lam was vague on this] of the records of people I had mailed books to as an exhibit to be used in court.

When they interrogated me, I didn’t know that they would ask Lee Po to copy the records in Hong Kong for them. They showed me the records on the computer and asked me directly who bought the books and what was my relationship with those people. I know now that they interrogated me according to the records provided.

I didn’t dare tell them about the readers because I was worried that those readers would be implicated, and then they would think that Hongkongers – or I – had betrayed them. But I didn’t do so.

They had the records but not the hard disk. I never thought they would use the trick and get someone to copy the records for them.

Now they’re even worse – they’re asking me to get them the actual hard disk.

I didn’t come back alone. There was a Mr Chan who came with me and a Mr Shi. This guy was good to me and had been looking after me. I am grateful for that.

I have now made this public...but my girlfriend, whom I met after separating [from my wife], she is still on the mainland and has been implicated. She’s also been seen as having broken the law because I had asked her to help me mail some books.

Similar to me, she’s now on bail and awaiting trial.

Also, I have colleagues who are in Hong Kong, with some needing to return to the mainland, like Lee Po and Lui Por. I hope that the Chinese government won’t mistreat my friends because of what I’ve done ... I hope the Chinese government will be courteous towards them, as God is good to humans. That is all I hope for.

I’ve been here for two days, but I haven’t slept at all. I had no source of information about what happened when I was on the mainland so I have been catching up on the news and news clips.

I was really touched, especially by the 6,000 people who took to the streets. These are all people who didn’t know me, who are all Hongkongers. But they could give me so much support, for the five of us – a little publisher and a bookstore. I’m very grateful.

Out of the five, I’m in a slightly different position ... At least I don’t have family on the mainland, only my girlfriend.

Of course I feel very sorry about my girlfriend, but I’ve thought hard and I know that this isn’t just something which involves me, but it implicates the whole of Hong Kong society. This is about the rights and freedoms of human beings.

The Chinese government has forced Hong Kong people into a dead end. This is our bottom line. Especially Lee Po, who was allegedly forcibly taken away in Hong Kong. This is something that I cannot accept.

If carrying out law enforcement duties across the border is really “one country, two systems”, I don’t need to discuss the problems such actions cause any further.

Let me say this again ... There is rule of law in Hong Kong and human rights are upheld, so I am not worried about my personal safety. I have no plans to go to the mainland again.

This is not just about me. This is about the freedom of Hong Kong people. The Chinese government has forced Hong Kong people into a dead end.

I just want to pass on a message: we here, including Hong Kong journalists, we Hong Kong people are all on the same boat. [The disappearances] can happen to you too for sure. If we don’t speak up, if I don’t speak up being the least of the five, then there is no hope for Hong Kong.

I had to be very courageous. I thought about it for two nights before I decided tell you all what happened, as originally and completely as I could.

I also want to tell the whole world. This isn’t about me, this isn’t about a bookstore, this is about everyone. This is the bottom line of the Hong Kong people. This is Hongkongers’ bottom line – Hongkongers will not bow down before brute force.