"... he went and made proclamation to the imprisoned spirits" 1 Peter 3.19
There is a controversial mediaeval doctrine called "the harrowing of hell", which contends that, on the day between his crucifixion and resurrection, so-called Holy Saturday, Jesus went and preached the Gospel to the inhabitants of Hell. In the Apostles Creed we declare "He descended into Hell". What did he do there?
We may never know for sure. The essential fact is that Jesus became sin for us so that we could rise with him to eternal life. The day between Good Friday and Easter Sunday is another opportunity to reflect in wonder at God's love and his power, caught between the crucifixion and the resurrection: the supreme examples of both.