"But I have to return."
Translation:Mas eu tenho que voltar.
Thank you. That is what my research was turning up as well (Even in Portugal. :D) though there are quite a few examples with the "de" as well.
I just cannot yet make sense of que in this use. My brain refuses to relate. Must make new neurons... which takes so much longer now that I am no longer under 10 years old. :(