At the end of Chapter 11, Attean offered Matt a treat that Indians enjoy. As they made their way through the forest,
"...he stopped, whipped out his knife, and neatly sliced off two shining gobs of dried sap froma nearby spruce. He grinned and held out one of them like a peace offering."
Popping one of the pieces into his own mouth and chewing "with evident pleasure," he ordered Matt to do the same. "Gingerly," Matt complied, and found that the gob fell to pieces between his teeth, filling his mouth with a bitter juice. Repulsed, he wanted to spit the mess out, but since Attean so clearly liked it, he doggedly kept chewing. Matt found that, after the initial taste of bitterness, the bits came together into "a rubbery gum" with "a fresh piney taste." The effect was quite pleasing, and the two boys forged on through the forest, enjoying their treats.
Matt had been feeling resentful because although Attean didn't really mean to, he had been making Matt feel stupid with his imperious manner in teaching him how to better navigate in the forest. Sensing that Matt was not happy, Attean had offered the treat, and Matt had to admit that Attean had, with all good intentions, shown him "another secret of the forest."
Attean Cheered Matt up at the end of chapter 11 because he gave Matt a second chance. Matt thought he wouldn't because Attean was really really furious the other day.