This expedition is nine parts death to one of life - don't take it lightly.
Tips
history
From Qu Yuan's 《离骚》 (Warring States Chu): 虽九死其犹未悔 - 'though I die nine deaths I would still not regret.' The Tang commentator Liu Liang glossed it as 九死无一生 - 'nine deaths with not one chance of life' - fixing the proportional reading that the idiom keeps today.
memory
The 九 (nine) is not literal - it's the classical way of saying 'many.' Read it as 'out of ten chances, nine say die, one says live' - a 90% death rate.