Freelance Traveller

Parasite: Mercurial Fluke

by Tom Bladon

This article originally appeared in the March/April 2024 issue.

The Mercurial Fluke is a fluke-like parasite native to the planet Mercury (Mora/2624 Spinward Marches). Given its name, many people think it is from the Sol system due the existence of a similarly named planet.

The Mercurial fluke is normally a parasite of the Mercurial mouse, a small rodent-analogue native to the planet. The mouse is eaten by the Mercurial fox, once inside the fox’s digestive system, the fluke matures, and starts producing eggs. These eggs then appear in the fæces of the fox and are eaten by the mouse, where it hatches and waits for the mouse to be eaten. The immature fluke sits in the gut of the mouse, causing the mouse to become slower and lethargic allowing it to be caught by the fox more easily.

ANIMAL	HITS	SPEED
Mercurial Mouse	2	4m
SKILLS	Athletics (dexterity) 1
ATTACKS	Bite 1
TRAITS	Fast Metabolism (+1), Small (-4)
BEHAVIOUR	Herbivore, Grazer

Morphology	Bilateral symmetry, quadruped
Biochemistry	C/H/O/N, broadly compatible with human
Respiration	Oxygen inhalant, Carbon Dioxide exhalant
Ecology	Metaturnal; Active throughout day and night hours
Habitat	Ubiquitous
Diet and Trophics	Herbivore, endothermic (warm-blooded)
Reproduction	Two genders, minor sexual dimorphism, conjugal intercourse, viviparous birth (litters of 3-8)
Lifecycle and ontogeny	½ year to sexual maturity; lifespan up to 3 years

Unfortunately the immature fluke can also infect other creatures causing similar symptoms. Anyone exposed to the fluke, must make an Easy (+4) Endurance check or be infected. If infected, the host becomes slower and more lethargic and can eventually just want to sleep all day. In game terms subtract 1 from Dex every three days. Once Dex reaches 1, then start subtracting from End. The main problem comes with constant reinfections, when eventually the healthiest of Travellers can eventually succumb. There are reports of Spaceships coming out of jump drives, where the entire crew have gone to bed and never bothered to wake up.

Sophonts are usually infected by their pets or on planets where the fox and mouse have been introduced. On any world where both live, the parasite can usually be found. Foxes have become feral on several worlds.

The two ways humans normally get infected are:

1. Handling an infected fox and not washing hands afterwards, especially when eating a meal.
2. Eating salads harvested from areas where a fox may have defecated.

The fluke is easily removed (cost Cr750) in any hospital, taking two days including recovery. Once removed the victim will return to normal (Dex and End return at the rate of 1 a day simultaneously).

Other organisms can become infected, as such the parasite has become a problem on several worlds infecting both wild and domestic animals.

Two things have caused the fluke to become a problem:

The Mercurial mouse can become a pest on spaceships and have spread to other worlds. They do not do much damage, managing to exist by eating crumbs that the crew leave behind.

The Mercurial fox makes quite good pets. They have become domesticated, and are for sale on several worlds in the Spinward Marches. They often have a certificate indicating that they are parasite free. These certificates are often fakes and if the buyer of a fox were to ever question why their pet was parasitised, the answer would be along the lines of,  ‘Must have been infected after you bought it guv’.

ANIMAL	HITS	SPEED
Mercurial Fox	7	8m
SKILLS	Athletics (dexterity) 1, Recon 1, Stealth 1
ATTACKS	Bite (1D)
TRAITS	Small (-1)
BEHAVIOUR	Carnivore; Pouncer and Scavenger

Morphology	Bilateral symmetry, quadruped
Biochemistry	C/H/O/N, broadly compatible with human
Respiration	Oxygen inhalant, Carbon Dioxide exhalant
Ecology	Diurnal, active during daylight hours
Habitat	Ubiquitous, adapted well to human company
Diet and Trophics	Carnivore, endothermic (warm-blooded)
Reproduction	Two genders, minor sexual dimorphism, conjugal intercourse, viviparous birth (litters of 3-8)
Lifecycle and ontogeny	1 year to sexual maturity; lifespan 10-12 years

If a Traveller suspects they have become infected they can be tested. The cost is CR20 for a self-test or CR50 for a qualified medic to do the test for you. To successfully perform the test is an easy (+4) Medic task. The subject will have had to be infected for about a week before the test can pick it up. Therefore duel tests are common where the subject is tested ten days apart, costing CR30 or CR75.

The best prevention to becoming infected, as always, is good hygiene.

Further reading on the inspiration:
https://en.wikipedia.org/wiki/Domesticated_silver_fox
https://en.wikipedia.org/wiki/Toxoplasmosis