top of page

M. K. Nadall is the writer's name of Hobart artist Mark Lleonart. He lives in a windswept lighthouse far, far away. The author is a science PhD, ukulele maker and the proud owner of a Wollemi pine. 


Letter from
Sir David Attenborough about Return of the Yggdrasil

Nisha Ward, reviewer for Reedsy

“Loved it! 😍

Funny, captivating and thought-provoking, this will make you rethink the way you look at trees.

What would you do if an alien species suddenly appeared and told you that eating plants was morally and ethically wrong? That plants had thoughts and feelings of their own? That you had to, somehow, learn how to photosynthesise sunlight to survive?

What would you do if this message were delivered via the inevitability that is the reality tv format?

I have to say, Return of the Yggdrasil handles this concept surprisingly well. Without sounding too preachy about it, the book spins a tangled web of science, comedy, and romance around the aliens in question that I was quite taken by.

The novel leans heavily on its character work to bolster this plot and boy howdy, does it do well in that department. Each of the main characters is impeccably developed, from Professor Niels Larsson to Jess Kelly to Matt Davis, and their supporting cast is a joy to read. The minor characters may be pure caricature, like Agent Cameron Peters and his crusade against the Yggdrasil, but it’s played more for comedy than for anything serious.

Rather, the heavy lifting is left up to Niels and his role as the leader of the Western Congress appointed by the aliens. As readers, we get to see a lot of him and what he feels about the aliens, from his awkwardness with Sif Acer, the chief spokesperson for the Yggdrasil, to his complex feelings about genocide and fighting back against the incursion of the less human-friendly sect of the species.

Admittedly, however, I did find that the environmental message was heavy-handed. After all, there are only so many ways you can be blunt about plant preservation and conservation before it begins to sound didactic. Additionally, it was quite annoying that the aliens were unwilling to be empathetic about the time it would take for wide-scale change to occur.

That being said, Return of the Yggdrasil is a rather fun book if you’re looking for easy-going sci-fi that challenges your ideas about environmentalism and human-plant co-habitation. Definitely a must-read on my end.” – Nisha Ward, reviewer for Reedsy


A lifelong reader, I've decided to share my opinions, my likes and my loves with the world. Fantasy and science fiction have long been passions of mine, but so has bringing minority voices to the forefront.

Return of the Yggdrasil on Triple J

Scientific & other publications

Lleonart, M. (1990). A gonad conditioning study of the greenlip abalone (Haliotis laevigata). Masters Thesis University of Tasmania.

Lleonart, M. (1991) Captive breeding of the greenlip abalone. Austasia Aquaculture Magazine 5, 29-30.

Lleonart, M.1997. Abalone Mud worms. In Proceedings of the 4 th annual abalone aquaculture workshop, Port Fairy.

Lleonart, M and Handlinger, J. 1998. Treatment of abalone mudworms. Proceedings of the 5 th annual abalone aquaculture workshop, Hobart (July)

Lleonart, M. 1999. Initial report: Abalone mud worm field studies on infection and progression patterns. In Proceedings of the 6 th annual abalone aquaculture workshop. World Aquaculture society conference, Sydney (April)

Lleonart, M. 1999. Mud Worm Treatment Trials. In Proceedings of the 6 th annual abalone aquaculture workshop. World Aquaculture society conference, Sydney (April)

Lleonart, M. (2000). Mudworm infestation of abalone and Pacific Oysters in Tasmania. Aquafest Australia 6-8 October, Hobart. Book of Abstracts p.81.

Lleonart, M. (2000). Minimizing the risk of mud worm infection in farmed abalone Proceedings of the 7 th annual abalone aquaculture workshop, Dunedin (August)

Lleonart, M. (2001). Australian abalone mudworms: avoidance and identification – A farm manual. Fisheries Research Development Corporation, Abalone Subprogram, 33 p.

Lleonart, M. (2001). A is for Antechinus surfing on a thong – an A to Z guide to Australian creatures. 30 pp.

Lleonart, M. (2002). Audiometry Notes for nurse training sessions 15 & 16 July 2002, Rosebery Community Hospital.33 pp.

Lleonart, M. (2002). Management of spionid mud worm infestations of Tasmanian cultured abalone. PhD Thesis, University of Tasmania, 240 pp.

Lleonart, M. (2004). Royal (Real) tennis racquet. Australian Wood Review Vol 42, p. 51 March.

Lleonart, M., Handlinger, J. and Powell, M. (2003). Treatment of spionid mud worm (Boccardia knoxi Rainer) infestation of cultured abalone. Aquaculture 217, 1-10.

Lleonart, M., Handlinger, J. and Powell, M. (2003). Spionid mudworm infestation of farmed abalone (Haliotis spp.). Aquaculture 221, 85-96.

Return of the Yggdrasil (2020 – published under pen-name MK Nadall). ISBN

Softcover: 9781034115885

O'Meley, C.,  Maguire, G. and Lleonart, M. (1992). Molluscan culture techniques : session 4 B [of the] Multi-Skilling in Aquaculture : a Hands-On Training Manual   National Key Centre for Teaching & Research in Aquaculture, University of Tasmania at Launceston,  39 p

Dineen, R., Gallagher, J., Johnson, M., Pirzl, H., Newton, P., Handlinger, J., and Lleonart, M. Chapter 11- Hydrocarbon content and histopathology of bivalves and fishes from IRON BARON oil impacted areas. In Iron Baron Oils Spill, July 1995: Long term environmental impact and recovery. Tasmanian Department of Primary Industries, Water and Environment.

IMG_3944 (2).JPG

Escaping from Cancer

bottom of page