We study the closure of the cubic Principal Hyperbolic Domain and its intersection P λ with the slice F λ of the space of all cubic polynomials with fixed point 0 defined by the multiplier λ at 0. We show that any bounded domain W of F λ \ P λ consists of J-stable polynomials f with connected Julia sets J(f ) and is either of Siegel capture type (then f ∈ W has an invariant Siegel domain U around 0 and another Fatou domain V such that f | V is twoto-one and f k (V ) = U for some k > 0) or of queer type (then a specially chosen critical point of f ∈ W belongs to J(f ), the set J(f ) has positive Lebesgue measure, and carries an invariant line field). 1 2 A. BLOKH, L. OVERSTEEGEN, R. PTACEK, AND V. TIMORINhas a non-repelling fixed point. As follows from the Douady-Hubbard parameter landing theorem [DH8485, Hub93], the Mandelbrot set itself can be thought of as the union of the main cardioid and limbs (connected components of M 2 \ PHD 2 ) parameterized by reduced rational fractions p/q ∈ (0, 1).This motivates our study of higher degree analogs of PHD 2 started in [BOPT14]. More precisely, complex numbers c are in one-to-one correspondence with affine conjugacy classes of quadratic polynomials (throughout we call affine conjugacy classes of polynomials classes of polynomials). Thus a natural higher-degree analog of the set M 2 is the degree d connectedness locus M d defined as the set of classes of degree d polynomials f , all of whose critical points do not escape, or, equivalently, whose Julia set J(f ) is connected. The Principal Hyperbolic Domain PHD d of M d is defined as the set of classes of hyperbolic degree d polynomials with Jordan curve Julia sets. Equivalently, the class [f ] of a degree d polynomial f belongs to PHD d if all critical points of f are in the immediate attracting basin of the same attracting (or super-attracting) fixed point. In [BOPT14] we describe properties of cubic polynomials f such that [f ] ∈ PHD d ; notice that Theorem 1.1 holds for any d 2.Theorem 1.1 ([BOPT14]). If [f ] ∈ PHD d , then f has a non-repelling fixed point, no repelling periodic cutpoints in J(f ), and all its non-repelling periodic points, except at most one fixed point, have multiplier 1.