HUELVA, Spain — Ruben Mendoza (“The Stoplight Society”), a leading light of Colombia’s new wave of young helmers, is set to direct his third feature, “Tierra en la lengua” (Dust on the Tongue).

A drama, “Dust” turns on two brothers who take a road trip to visit their tyrannical but now-ill grandfather. At the grandfather’s farm in the primitive beauty of Colombia’s Eastern Plains, their grandfather asks them to kill him. But his grandsons discover step-by-step his past and finally decide to prolong his agony as long as they can.

“Dust” is “an exercise in personal exorcism of a marvellous and horrible monster, my maternal grandfather,” Mendoza told Variety.

“His power, madness and bitterness continue to seep into our family, myself included,” he added.

Also written by Mendoza and moved onto the terrain of fiction, “Dust” is set up at Mendoza’s Bogota-based Diafragma Fabrica de Peliculas. Diafragma producer Daniel Garcia will produce. “Dust” is skedded to shoot February, before the rainy season on the Plains, Garcia said in a pitch at the 2011 Huelva Co-Production Forum, which kicked off Thursday.

It has pulled down a $350,000 grant from Colombia’s powerful Film Development Fund (FDC). With 70% of “Dust’s” budget covered, Diagragma is now looking to international film funds or co-production for completion finance, Garcia said.

That should not prove too tough a call for Mendoza and Garcia.

A rambunctious vision of Colombian street-life, “Stoplight,” which topped the 2010 Huelva Ibero-American Festival, achieved the by-no-means mean feet of sourcing finance from France’s Fonds Sud Cinema, Ibermedia, Colombia’s FDC, Switzerland’s Visions Sud Est and Berlin Festival’s World Cinema Fund.

Earlier this month, Mendoza finished shooting his second feature, “Cuasi Morido” (Practically Dead), a mockumentary spin-off from “Stoplight,” which he calls “a very low-budget, very-guerrilla film.”

“Dust” was developed at the early 2011 Cannes Festival Cinefondation Residence.