Fatal is a synonym of Inevitable. Inevitable is the opposite of Possible. Possible is the opposite of Actual. Actual is the opposite of Future. 
Like is related to Let. Let is the opposite of Keep. Keep is related to Reserve. Reserve is related to Agreement. 
Fatal <--Synonym--> Inevitable <--Antonym--> Possible <--Antonym--> Actual <--Antonym--> Future 
Like <--RelatedTo--> Let <--Antonym--> Keep <--RelatedTo--> Reserve <--RelatedTo--> Agreement 