Different is a synonym of Unusual. Unusual is a synonym of Odd. Odd is the opposite of Expected. Expected is related to Payment. 
Join is related to Activity. Activity is related to Employment. 
Different <--Synonym--> Unusual <--Synonym--> Odd <--Antonym--> Expected <--RelatedTo--> Payment 
Join <--RelatedTo--> Activity <--RelatedTo--> Employment 