undertow

(ŭnˈdər-tōˌ)

1. An underwater current flowing strongly away from the shore, usually caused by the seaward return of water from waves that have broken against the shore.
2. A tendency, especially in thought or feeling, contrary to what seems the strongest: “As she talks nostalgically of her days of glory . . . a poignant undertow emerges” (Tina Brown).