Mark is a writer, an author, a researcher and a community worker. His first book, The Undesirables: Inside Nauru (Hardie Grant, 2014), is an account of his work with asylum seekers in Nauru, one of Australia’s notorious offshore detention centres. His second book, Nauru Burning (Editia, 2016), follows up The Undesirables with an investigative report on human rights abuses on Nauru. In 2017, Mark conducted an investigation into deportations to Afghanistan with the Edmund Rice Centre. The published report, titled 'Responsibility to Protect', paved the way for Mark's later writings in Afghanistan.
Mark’s third book, The Kabul Peace House (Hardie Grant, 2019) is about a community of peace activists in Afghanistan. Mark is president of Sydney PEN, an affiliate of PEN International, a worldwide association of writers which defends freedom of expression and campaigns on behalf of writers who have been silenced by persecution or imprisonment. He continues to write freelance while studying a Doctor of Philosophy at the University of Technology, Sydney. His research will focus on human migration in the Asia-Pacific region.