The 25 pictures in a cluster foxer are arranged in 5 discretely/discreetly themed clusters. Pictures in a particular cluster must be cardinally contiguous to be valid. For example, a1, a2, a3, a4, b4 is a possible cluster, unlike c1, c2, c3, c4, d5.
To fully defox today's enlargeable puzzle identify the themes and constituent images of all five clusters.
* * *
Last week's geofoxer theme: Tintin (defoxed by phlebas)
a. Tintin and the Golden Fleece (Gothnak)
b. Flight 714 (Gusdownnup)
c. Tintin in Tibet (Teek)
d. General Alcazar (Gothnak)
e. The Secret of the Unicorn (phuzz)
f. Nestor (Gothnak)
g. Marlinspike (Gothnak)
h. Thomson and Thompson (phlebas)
i. The Black Island (Gothnak)
j. The Shooting Star (AFKAMC)
k. The Blue Lotus (phuzz)
l. Tintin murals (Gusdownnup)