Byambyn resides in Siberia. He has an extensive family, including his elder sister Namgar.
Byambyn offers to take Passepartout and Phileas Fogg with his caravan headed for Urga, potentially helping Passepartout reunite with Goland. He brings his family with him to visit relatives along the Selenga river. Unfortunately this includes his prankster cousins who sneak spiders into Passepartout's bedclothes.
Along the way, the group meet escaped convict Veruschka. Byambym expresses fear of being caught with her by the Cossacks, but takes her with them at the insistence of Namgar and potentially Passepartout and Fogg. The group can smuggle her into the city or leave her outside to fend for herself once more, after which Byambyn bids Passepartout and Fogg farewell.
Byambyn tends to his extensive family, and is shown to be a tad oblivious or accepting of the younger children's mischievous activities. He is also somewhat fearful, shown when he is reluctant to take Veruschka with the group, but did so at his sister's insistence, showing where his priorities lie.