is Waiyaki and Muthoni the bridge between the two cultures

I think this can be seen as a true statement. Waiyaki keeps building more schools in an attempt to provide education to the people, but even though he has good intentions, he underestimates the power of the council of the elders, who consider adhering to ancient traditions more important than taking over parts of the white man's culture. In the end, he is punished by the council and the people, which indicates that all his efforts were in vain. Similarly, Muthoni goes against the will of her father and Christian community when she decides to follow the traditions and get circumcised to become part of the tribe. Muthoni dies because of this procedure, which also indicates that reconciliation is impossible.