London has been at its coldest in two years. A black cab is moving swiftly towards Samarkand, an Uzbeki restaurant on Charlotte Street not very far away from the BBC’s office in Portland Place where Muhammad Iqbal or Iqbal Lala has just given three back-to-back interviews. Last year in April, his 25-year-old son Mashal Khan was lynched by an angry mob at Abdul Wali Khan University in Mardan over fake allegations of posting blasphemous content on social media. Inside this cab, next to Lala sits Ziauddin Yousafzai, Malala Yousafzai’s father. Just two days prior to this, the two spoke about Mashal Khan’s legacy and the work of Bacha Khan at the School of Oriental and African Studies (SOAS) in a talk organised by Bloomsbury Pakistan.

Iqbal Lala switches from Urdu to Pashto when he talks to Yousafzai. As he does so, his body opens up, he leans back and moves his arms animatedly. The conversations tend towards lightness when this happens. Lala smiles but, despite his best efforts, his face permanently carries the expression of a haunted man.

Our phones buzz with a new notification. In Charsadda, a student has shot his principal over a dispute for missing classes. "The student missed classes because he was attending rallies held in favour of the country’s blasphemy law by Tehreek-e-Labaik," explains Yousafzai. Lala is silent but his gaze is growing more restless as we drive through London.

We arrive to find that Samarkand is closed, and decide on walking towards Drummond Street for Pakistani cuisine. Lala walks with me, two steps behind the rest of the group. His hands clasped behind his back, chin bent but shoulders square he strides purposefully against the wind.

"You know this violence had no place among Pashtuns. The current generation, it is so unfortunate, has not seen peace. They do not know of a different reality," he begins.

"There was a time when houses had no doors. A curtain would be enough for privacy. We would have festive melas. Women participated in social life. I can still hear the melodious sound of the rabab ringing in my ears," he continues with what looks like the hint of a smile.

"I grew up in such a time," he remarks.

"I got diploma in Urdu. As a young boy, I was exposed to progressive Urdu literature, as well as Pashto literature - especially poetry of resistance. As I grew up, the topics I wrote on became more serious. It also had to do with the fact that I became deeply involved in politics and was a follower of Bacha Khan."

How much of himself did he see in his son? I ask him.

"We had a great relationship. My thoughts did influence Mashal but to a very limited extent. He had his own perspective. He had travelled as far as Russia where he went to study - an experience that further expanded his mind. I had never been to university. He also read a lot of books," he tells me.

Mashal Khan wanted to become a journalist and Lala was convinced that his "smart and hardworking boy" did have the aptitude to do well in the field. But, his son’s dreams were cut short because of his "irreverence to the status quo".

"He told his mother that he would be back on Friday. Well, his body reached us on Friday," he remembers.

But, Lala’s voice is clear and steady. His composure and lucidity is astounding. Each time he is interviewed he says just about enough to draw attention to the fact that his story is representative of a more pervasive and dangerous social malaise spreading in Pakistan. His son may be his son; but he is also a vantage point from which the extent of societal decay can be examined.

"He was shot at, pelted with stones, and beaten with rods. Then his lifeless body was stripped. It was heart-breaking. I couldn’t lose my courage. I couldn’t break down. What would happen to his mother if I did?" he asks.

Then came another test for Mashal Khan’s family - arranging his funeral. Even in their mourning, they were put through a devastating ordeal. A ‘blasphemy allegation’ had resulted in Mashal’s horrific murder, and this would make even his funeral a battle. The family had to act quickly and look for a maulvi to officiate.

Lala’s trauma has been translated in three different languages by the BBC.  His responses are cautious and thoughtful. They are political; bigger than his pain. But it is his silences that weigh heavier than his considered words.

His son’s case is in its final stages. The KP government promised financial support to Mashal Khan’s family for the legal proceedings but those promises have not materialised. The statements of the 57 accused in Mashal Khan’s murder have just been recorded for cross-examination. It is unclear how much time the entire process will take. The lawyers representing him are not charging any fee for their services. Lala is determined to seek meaningful justice so that "no parents have to ever weep for their Mashal".

"Mashal Khan exposed the university’s corruption and injustices - an absent Vice Chancellor, absent professors and the rising fee that the students were finding hard to cope with. That was the reason why he was killed. AVT Khyber interviewed him on the matter and whatever happened to him happened after that," he says.

Mashal Khan too, did not let on any signs of emotional distress before he was murdered, Lala stresses repeatedly. But he left Lala a diary containing poetry he had written himself. A Pashto verse that Lala can remember from that diary roughly translates into: "If you have to kill me to put food on your table so that your children don’t go hungry, do so; But listen to me, I am not an infidel".

Who did he think his son was addressing?

"The powers that be," he says quietly.

We have arrived at our destination. Lala is tired now, and needs to replenish his strength for his travel. We place our order quickly. And over the dinner table, the conversation ranges from music to history. There is some banter. Lala smiles but his eyes still seem to be frozen in time.

"We cannot lose hope. We have to take this mission forward. Mashal Khan’s legacy has to be kept alive," he says as we part.

He walks away with the same unwavering determination, hands clasped behind him - the silhouette of an injured but determined hawk.

"Pakistan produces people of extraordinary bravery but no country should ever require its citizens to be that brave", wrote Nadeem Aslam. Iqbal Lala came to London carrying mountains on his back but a gaze still turned skyward - a perspective oriented towards the sun. But should he have had to?

An earlier version of the story erroneously stated that Lala appeared completed his Bachelors in Urdu Literature as a private candidate.