Apartheid was the racial segregation system in South Africa from the end of WW2 up into the mid-90s. Under this system, people were assigned to one of four racial categories. Only the white category had political power, citizenship, passports, and full education, along with better facilities and looser laws. Non-white people were assigned to specific areas to live (which were always much inferior to the white areas).

The African National Congress (ANC) was a socialist organisation created in response to racial crackdowns in South Africa; during the apartheid era it was the dominant anti-apartheid force. Nelson Mandela was the most famous leader of the ANC and was imprisoned by the apartheid-era government for it for ~30 years.

During the 1980s, many groups and nations around the world enforced sanctions on South Africa, demanding that it end apartheid. The Reagan government in the US was a notable exception to this and vetoed efforts to have UN sanctions applied, declaring itself allied with the South African government and opposed to the socialist ANC. The USSR supported the ANC and sanctions on South Africa.

In the show currently, Hans is one of those protesters, a white South African opposed to apartheid and active in an anti-apartheid group.

Todd is a student who is also part of those protest groups, but who Hans has identified as a spy. Todd wants to stage attacks under a red banner to damage the reputation of the anti-apartheid movement.

NcGobo is a black South African militant aligned with the ANC.

Venter is a South African agent aiming to assassinate NcGobo. The Center knows that NcGobo is a target.

Elizabeth recruits Hans, who identifies Todd as a spy. They then arrange for NcGobo to meet with Todd (who purports to be a left-wing anti-apartheid activist), knowing that Todd will report this and that Venter will be dispatched to their meeting. When Venter is drawn out, Philip attacks him on the street. Elizabeth identifies Venter's spotter/backup (the woman with the baguettes, who reveals her South African accent) and kills her.

She drives her van out. Philip drags Venter into it while NcGobo drags Todd into it. That's where we are now.

The personal upshot of this whole affair is that Paige's burgeoning conservativism has come into conflict with her anti-racism and sympathy for the anti-apartheid cause, providing an opportunity for her turn.