We consider a recursive system (X n ) which was introduced by Collet et al. [10]) as a spin glass model, and later by Derrida, Hakim, and Vannimenus [13] and by Derrida and Retaux [14] as a simplified hierarchical renormalization model. The system (X n ) is expected to possess highly nontrivial universalities at or near criticality. In the nearly supercritical regime, Derrida and Retaux [14] conjectured that the free energy of the system decays exponentially with exponent (p − p c ) − 1 2 as p ↓ p c . We study the nearly subcritical regime (p ↑ p c ) and aim at a dual version of the Derrida-Retaux conjecture; our main result states that as n → ∞, both E(X n ) and P(X n = 0) decay exponentially with exponent (p c − p) 1 2 +o(1) , where o(1) → 0 as p ↑ p c .