And when he finished, he put flowers in her hair and led her across the bridge – the great bridge into Terabithia – which might look to someone with no magic in him like a few planks across a nearly dry gully. (13.82)
Jess's loss makes him value Terabithia even more, while also realizing its impermanence and value. Even as he crosses "the great bridge into Terabithia" with the help of his ever-growing imagination, he knows what the entrance to Terabithia would look like to an outsider – just some wood "planks." But Jess is someone with "magic in him," and that magic isn't borrowed or reflected from Leslie's magic – it's magic of his very own.