Always a man who feels things deeply, he had to halt his speech several times for long periods as he fought back the tears. Captain of New Zealand, a batsman who faced some of the world's most feared bowlers and the pressure of this country's sporting expectations, this is maybe his toughest innings.
Downes had to move up on stage to settle him at one point. MC Keith Quinn later told the story of how Marty and Lorraine had invited him back to their place once to watch an All Blacks test. The game began with all of them on the couch, watching the TV with glasses of wine in hand. Lorraine drifted away. Then Marty got up, leaving Quinn on his own. After a long while, Quinn got up to investigate. He found them dancing together in the kitchen. No music, just dancing.
She led him through the next steps of his speech and then melted back into the crowd along with good mates Grant Fox, AGS contemporary and now an All Black selector to go with that stellar All Black record, and Dave Morris, head prefect at Grammar when Marty was deputy head prefect.
Many thought he was overcome with emotion at what he'd been through and the relief of the just-announced disappearance of his cancer. Maybe he was. Those of us in the audience who have also survived cancer had a slightly different spin on it.
He wasn't choked up by what had happened to him; he was weeping for what he had - life, Lorraine, daughter Emma, strong friendships, his mum Audrey, the memory of his dad Dave, a good glass of red wine, a clear view of life, an openness instead of a tendency to hold poisonous thoughts in his head ... a second innings.
He described how, when he was diagnosed with cancer, he was put into a "watch and wait" group. Then the Ross Taylor captaincy kerfuffle broke; he got involved - and discovered that he had grown a tumour. He believes the two things are directly related; the poison of negative thoughts spread within his body.
"I realised that I had to dispense with hurt and deep-seated resentment - and I had a lot of that," he told the audience.
So cricket, previously his reason for being and that which defined him as a sportsman and a man, had to go. Those of us who spoke to him in the aftermath of the Taylor affair and during his five months of chemotherapy know that he opted out of the John Parker-led campaign against the board of New Zealand Cricket.
"Like an alcoholic with a glass of wine, I knew cricket had to go."
The second half of his book is a farewell to the sport about which he cares deeply but fears can do him no good at this stage of his life.
The book also lays to rest other issues which have diverted and damaged him throughout his life; a beneficial expurgation, sending all that negativity into the ether via words on a page.
It was a powerful book launch and a unique one. It's very different from the last book he wrote, also an autobiography but launched at the same time Joseph Romanos (ironically, publisher of Raw) launched the then unauthorised biography of Martin Crowe, called Tortured Genius.
He'll probably not write another book - not on cricket anyway. So there'll be more time for dancing in the kitchen with Lorraine and more time with one of nature's great gifts - a daughter - and more time to enjoy what he has fought for and won: life.