Abstract. The paper contains a new proof that a complete, non-compact hyperbolic 3-manifold M with finite volume contains an immersed, closed, quasi-Fuchsian surface.A complete finite-volume hyperbolic 3-manifold with cusps is a non-compact hyperbolic 3-manifold with finite volume and universal cover hyperbolic space. We give a new proof of the following result of Masters and Zhang [11], [12].Theorem 0.1. Suppose M is a complete finite-volume hyperbolic 3-manifold with cusps. Then there is a π 1 -injective immersion f : S −→ M of a closed, orientable surface S with genus at least 2 and f * (π 1 S) is a quasi-Fuchsian subgroup of π 1 M .Cooper, Long and Reid [6] showed that such manifolds contain geometrically finite closed surface groups but there might be accidental parabolics. Kahn and Markovic [9] have shown that a closed hyperbolic 3-manifold contains an immersed QF (quasi-Fuchsian) surface.A prefabricated 3-manifold, Z, is the union of a finite number of convex pieces, each of which is either a rank-2 cusp or a QF manifold Q i with rank-1 cusps. We require simple combinatorics: there are exactly two rank-1 cusps, with slopes that intersect once, inside each rank-2 cusp of Z. See (1.1) for the precise definition. The convex combination theorem [2] is used to ensure Z has a convex thickening, CH(Z). In this case ∂Z consists of closed incompressible surfaces without parabolics. The main theorem follows from (1.2) which says there is a covering space of M that has a convex core which is a prefabricated manifold. This construction of QF surfaces is similar to the method used in [2] and [5].The crucial step is to control how the QF manifold pieces of Z intersect. In section (3) we study the intersection Q 1 ∩ Q 2 of two QF manifolds with cusps. This is governed by a finite collection of convex subsurfaces immersed by local isometries into ∂Q i . A compact core of Q i is homeomorphic to an interval times a compact surface F . A spider is a compact subsurface X ⊂ F , satisfying certain conditions. After taking finite covers, each component of Q 1 ∩ Q 2 is described by a spider.The crucial step relies on a result about surfaces: the spider theorem (2.5). Each component of X ∩ ∂F is an arc called a foot of the spider X. We show that if every component of ∂F contains at least one spider foot then, after replacing F by a suitable finite cover of F , and choosing certain lifts of the spiders, every boundary component of F contains exactly one spider foot. This ensures the above mentioned simple combinatorics for Z.In section (5) we discuss the relation between our proof and that of Masters and Zhang. Acknowledgements: The authors thank IHP and Université de Rennes 1 for hospitality during completion of this work.