David Ormerod (the author) says: Black can paralyze white with a single blow to the vital point.
(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
SO[http://gogameguru.com/]AW[qk][no][ip][nq]AB[qm][pn][lp][pp][oq]C[Black to play.
How can black connect his all stones?
http://gogameguru.com/]
(;B[mq]
(;W[np]
;B[nr]C[RIGHT])
(;W[nr]
;B[np]C[RIGHT]))
(;B[np]
;W[mp]
;B[op]
;W[mo]
;B[mq]
;W[lq]
(;B[nr]
;W[mr])
(;B[mr]
;W[lr]
(;B[nr]
;W[kp]C[This is a kind of net, not really a ladder.]
;B[lo]C[If black tries to escape...]
;W[ln]
;B[ko]
;W[jn]
(;B[jp]
;W[jo]
;B[kq]
;W[kn]
;B[kp]
;W[kr])
(;B[jo]
;W[io]
;B[jp]
;W[jq]
;B[kq]
;W[kn]))
(;B[kp]
;W[nr])))
(;B[nr]
;W[mq])
(;B[ln]C[Black can attack on a large scale too.]
;W[lq]
;B[kq]
;W[kp]C[White can manage the situation lightly like this. Other moves are possible too.])
(;B[ko]
;W[mr]LB[nm:A][kq:B]C[A and B are miai for white next.]))