Tak is a clay-like mineral, found on Denduron, that has explosive qualities. It was supposed that tak was very natural to Denduron. Figgis, a greedy merchant, found the tak years ago on the mine of Denduorn. The Milago used the tak against the Bedoowans.
In The Merchant of Death
On Denduron, the Milago were about to wage war against the Bedoowan using Tak. This would have been the turning point for Denduron, because if the Milago used Tak, they would use it more so they could become the most powerful tribe on Denduron. They were planning on Queen Kagan and most of the Bedoowan Knights by exploding a large cart filled with Tak, topped with Glaze to disguise it. The act was supposed to have been carried out by Rellin, Chief Miner, but it was interrupted in time. Milage used slingshots to throw the Tak at the Bedoowan Army, but the Bedoowan countered it by making a shell out of their shields and so Bobby had to leave before the grisou killed him. but before that he blew up a massive vain in the mine of tak uniting the 2 colonies from the destruction
In The Pilgrims of Rayne
Bobby Pendragon brought a Dygo from Zadaa to Denduron so he could mine for Tak. He needed the Tak to take back to Ibara and fight the Dados that Saint Dane brought. The battle ended when Bobby used a large amount of Tak to destroy all of the Dados at once, as well as the village of Rayne. He ended up using an arrow with Tak on it to try and trap Saint Dane on Ibara, along with himself.
In Raven Rise
When Alder travels backs to his own home territory, he notices that the Milago tribe have upgraded their strategy with tak, resulting in tak cannons.