Lumin is a strange, magical addictive, sickly green light that gives pleasure to the user but dulls their mind and senses. When Lumin is taken, the user's body malfunctions and is showered in green light. While in use, the user's arms are flung upwards and foaming at the mouth and eyes rolling back, showing only the whites, can occur.
Return to Del
Lumin was given to Fallow by Shadow Lord for his pleasure in his place of exile. However, the drug dulled his mind and made him forsake his duties frequently, for which the Shadow Lord threatened to remove it. Fallow's use of Lumin was well known among the Shadow Lord's servants, and both Grey Guards and Ols insulted him behind his back for using it.
Lumin and Fallow's addiction to it may be Emily Rodda's attempt to comment on drug abuse and drug addiction.